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MathematicsCh 10 Conic Sections

Conic Sections: Class 11 Maths Chapter 10 Hinglish mein

Mathematics · Hinglish notes, simulations aur practice · Official NCERT chapter PDF ↗

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  • 100 min
  • 3 simulations
  • 44 practice questions
  • 23 MCQs

Is chapter mein aap kya seekhenge

  • Samjhana ki ek double cone ko kaatne wala plane apne angle ke hisaab se circle, ellipse, parabola, hyperbola ya degenerate conic kaise deta hai.
  • Centre aur radius se circle ki equation likhna, aur completing squares se equation se centre aur radius nikaalna.
  • Parabola ki focus–directrix definition aur ellipse aur hyperbola ki two-focus definitions batana, aur unki standard equations derive karna.
  • Standard equation se focus, vertices, axes, eccentricity aur latus rectum padhna, aur aise data se equation banana.
  • Ellipse ke liye a² = b² + c², hyperbola ke liye c² = a² + b² aur e = c/a use karke ek parameter se doosre tak jaana.
  • Reflectors, arches, cables aur sliding rods ko conics se model karna aur unse bane problems solve karna.

NCERT Mathematics Class 11, Chapter 10, pp. 176–207 par based original companion text. Yeh NCERT se juda nahi hai aur NCERT ne ise endorse nahi kiya hai.

10.1 Introduction

Torch ko seedha floor ki taraf neeche point karo, to light ka patch ek gol disc hota hai. Torch ko thoda tilt karo, to disc khinch kar oval ban jaata hai. Aur tilt karo, to patch ka door wala sira floor par bhaagta chala jaata hai aur kabhi band nahi hota. Beam light ka ek cone hai aur floor ek flat plane hai, isliye tumne jo bhi outline dekhi woh ek plane dwara cone se kaata gaya curve hai.

2/3Tilt karne par: patch khinch kar oval ban jaata hai.

Fig. 10.1Torch tilt karne par uska light ka circle pehle ellipse aur phir khula parabola ban jaata hai.

Upar: level floor ke upar ek torch ka side view, uski beam dashed edges wale halke cone ki tarah bani hai aur floor ka roshan hissa green mein mark hai. Neeche: wahi roshan patch upar se dikhta hua. Step 1: torch seedha neeche point karti hai aur patch ek gol circle hai. Step 2: torch tilt hai aur patch khinch kar ellipse ban jaata hai. Step 3: torch itni tilt hai ki beam ka upar wala edge floor ke parallel chalta hai, aur patch kabhi band nahi hota: uski outline ek parabola hai.

Chapter 9 mein tumne straight lines ko equations se describe kiya tha. Yeh chapter chaar curves ke liye wahi karta hai: circle, ellipse, parabola aur hyperbola. Kyunki yeh chaaron cone ko kaatne se aate hain, inhe conic sections (शंकु परिच्छेद) ya simply conics kehte hain.

Dhyaan se dekho to yeh curves har jagah hain. Planets aur comets ellipses par chalte hain. Maidaan mein phenki gayi ball parabola follow karti hai (agar hum air resistance ko ignore karein), aur parabolic shapes DTH dish mein signals ikattha karti hain aur car headlamp ki beam ko focus karti hain. Kai power-station cooling towers ki kamar jaisi sides hyperbolas hain, aur satellite navigation se pehle hyperbolas ne ships ko radio se apni position pata karne mein bhi madad ki.

Quick check
2 mein se 1
Ek torch seedha level floor ki taraf neeche point karti hai. Uske light ke patch ka edge hai
Answer dekho

Answer (B) ek circle

Jab beam floor ke square hai, to har edge ray barabar distance tay karti hai, isliye patch gol hota hai. Torch tilt karne se woh khinch kar ellipse banta hai aur phir khul kar parabola ban jaata hai.

10.2 Cone ke Sections

Double-napped right circular cone do khokhle cones hain jo nok se nok jude hain, aur dono bina ruke aage badhte jaate hain (Fig. 10.2). Ise banane ke liye do lines kaafi hain. Ek vertical line l ko fixed rakho. Uske ek point V se ek line m banao jo l se acute angle α par ho. m ko l ke around ghumao, jaise ek spoke axle ke around ghoomti hai, aur α ko fixed rakho: m ki saari positions milkar surface banati hain.

3/3Bani hui surface: do nappes jo vertex V par milte hain.

Fig. 10.2Line m ko axis l ke around ghumane se ek double cone banta hai.NCERT Figs 10.1, 10.2 · p. 176

Ek vertical dashed axis l aur ek tirchhi line m jo use point V par kaatti hai; dono ke beech ka angle alpha mark hai. Step 1 mein sirf do lines hain. Step 2 mein m ki kai positions par halki copies aur upar-neeche dashed rings judte hain, saath mein ek arrow jo dikhata hai ki m, l ke around ghoom rahi hai aur alpha fixed hai. Step 3 bani hui surface ko shade karta hai: V par milte do cones, jin par upper nappe aur lower nappe likha hai, V ko vertex, l ko axis aur m ko generator mark kiya gaya hai.

Kuch naam: milne wala point V vertex hai, fixed line l axis hai, aur apni kisi bhi position mein m ek generator hai. V ke upar aur neeche surface ke do halves hain, upper aur lower nappes.

Ab ek flat plane lao. Yeh cone ko jahan bhi kaate, kaate gaye hisse ka edge ek conic section hota hai, aur uska shape sirf do cheezein decide karti hain: plane ka axis se angle β (jise cone ke angle α se compare karte hain), aur yeh ki plane V se guzarta hai ya nahi.

10.2.1 Circle, ellipse, parabola aur hyperbola

Pehle plane ko vertex se door rakho. Plane ko axis ke square rakh kar shuru karo aur use thoda-thoda tilt karo:

  • β=90∘: plane axis se right angle par hai aur cut ka edge ek circle hai.
  • α<β<90∘: plane tilt hai lekin ab bhi ek nappe ko poora paar karke kaatta hai, isliye cut ek band oval hai, yaani ellipse.
  • β=α: plane ek generator ke parallel hai, isliye us side par woh cone se dobara kabhi nahi milta aur curve khula rehta hai; yeh parabola hai.
  • 0≤β<α: plane cone ki side se zyada steep hai aur dono nappes ko kaatta hai, jisse hyperbola ki do alag branches milti hain.

4/7Cone se zyada steep: dono nappes kat jaate hain, ek hyperbola.

Fig. 10.3Kaatne wale plane ka angle decide karta hai ki kaun sa conic milega.NCERT Figs 10.4–10.10 · p. 177

Left: side se dikhta double cone, jismein uska axis aur vertex V par angle alpha mark hai. Ek dashed line plane ko edge-on dikhati hai aur ek moti green line dikhati hai ki plane cone se kahan milta hai. Right: ek panel cut ka asli shape, uska naam aur beta ki condition dikhata hai. Step 1: horizontal plane se circle milta hai. Step 2: ek nappe ke aar-paar tilt plane se ellipse milta hai. Step 3: generator ke parallel plane se khula parabola milta hai. Step 4: vertical plane dono nappes ko kaatta hai aur do branches wala hyperbola deta hai. Steps 5 se 7 mein plane V se guzarta hai: horizontal plane cone se sirf V par milta hai (ek point), generator ke saath wala plane ek line deta hai, aur axis se guzarta vertical plane do kaatti lines deta hai.

Pattern dekho: plane jitna steep kaatta hai, curve utna zyada khulta hai. Circle aur ellipse band hain aur ek nappe par hain; parabola ek nappe par hai lekin khula hai; hyperbola khula hai aur use dono nappes chahiye.

10.2.2 Degenerated conic sections

Ab plane ko vertex V se guzarne do. β ki wahi teen ranges conics ke pichke hue versions deti hain, jinhe degenerate conics kehte hain (Fig. 10.3 ke steps 5 se 7):

  • α<β≤90∘: plane cone se sirf V par milta hai, isliye section ek single point hai.
  • β=α: plane ek generator ke saath-saath padta hai, aur section wahi straight line hai. Yeh degenerate parabola hai.
  • 0≤β<α: plane do generators ke saath dono nappes se guzarta hai, jisse pair of intersecting lines milta hai. Yeh degenerate hyperbola hai.

Yahan se hum cone ko ek taraf rakhte hain. Har curve ko plane mein distances ke ek simple rule se describe kiya ja sakta hai, aur woh rules seedhe equations tak le jaate hain.

Quick check
3 mein se 1
Plane vertex se nahi guzarta. Angle β ko curve se match karo.

Left mein koi item tap karo, phir right mein uska match.

Answer dekho
Answer
  • β=90∘ : circle
  • α<β<90∘ : ellipse
  • β=α : parabola
  • 0≤β<α : hyperbola
Plane ko square position se tilt karne par curve khulta jaata hai: circle, phir ellipse, phir parabola jab plane generator ke parallel ho, phir hyperbola jab woh itna steep ho ki dono nappes tak pahunch jaaye.

10.3 Circle

Definition
Circle

Plane mein ek point C aur ek positive number r fix karo. Centre C aur radius r wala circle us plane ke un sabhi points se banta hai jo C se distance r par hain.

Is rule ko equation mein badalne ke liye centre ko C(h,k) par rakho, radius ko r kaho, aur P(x,y) ko plane ka koi bhi point maano. P circle par tabhi hai jab CP=r. Distance formula ek right triangle ke do legs se CP deta hai, aur square karne se square root hat jaata hai (Fig. 10.4).

2/3Legs hain x−h aar-paar aur y−k upar.

Fig. 10.4Radius ke neeche bane triangle mein Pythagoras se circle ki equation milti hai.NCERT Fig. 10.12 · p. 180

Coordinate axes ke saath ek circle jiska centre C(h, k) first quadrant mein hai. Step 1 mein C ko circle ke ek point P(x, y) se radius r dwara joda gaya hai aur CP = r likha hai. Step 2 radius ke neeche ek right triangle banata hai: x minus h length ka horizontal leg aur y minus k length ka vertical leg, aur panel batata hai ki (x minus h) squared plus (y minus k) squared equals r squared. Step 3 circle par teen aur points jodta hai, har ek C se same length r ke radius se juda hai, yeh dikhane ke liye ki circle ka har point same equation follow karta hai.

Circle: centre (h, k), radius r
(x−h)2+(y−k)2=r2
(10.1)

Circle ka har point (10.1) ko satisfy karta hai, aur jo bhi point ise satisfy karta hai woh C se distance r par hai, isliye yeh equation circle ko bilkul sahi describe karti hai. Centre origin par ho to yeh x2+y2=r2. ban jaati hai.

(10.1) ko expand karne par x2+y2−2hx−2ky+(h2+k2−r2)=0 milta hai. Isliye circle ki equation mein x2 aur y2 ke coefficients barabar hote hain aur koi xy term nahi hota. Ulti taraf se, neeche wale form ki equation ko completing squares se padha jaata hai:

General form
x2+y2+2gx+2fy+c=0
(10.2)
jahan
(−g,−f)
centre
g2+f2−c
radius, jab g2+f2−c>0

Agar g2+f2−c=0 ho to “circle” sikud kar single point (−g,−f) ban jaata hai, aur agar yeh negative ho to koi bhi real point equation ko satisfy nahi karta. Agar x2 aur y2 ka coefficient 1 nahi hai, to pehle usse divide karna padega.

SimulationC se distance 5 par points

Dono axes par minus 8 se 8 tak ek coordinate grid. Ek fixed point C (1, minus 2) par hai aur ek draggable point P (4, 2) se shuru hota hai; segment CP apni length ke saath bana hai, aur move karne par P grid points par snap hota hai aur apne coordinates dikhata hai.

Fig. 10.5P ko drag karo aur distance CP dekho. Circle woh saare points hain jahan yeh 5 dikhata hai.
Try karo
  • P (4,2) par shuru hota hai aur CP=5 hai. Woh saare baarah grid points dhoondho jinke liye CP=5 ho.
  • Har mile hue point ke liye check karo ki (x−1)2+(y+2)2=25 hai.
  • P ko (3,0) par rakho. Kya CP 5 se zyada hai ya kam? P circle ke andar hai ya bahar?
Example 10.1NCERT Example 1 · p. 180

Centre origin par

Origin par centre wala ek circle (5,−12) se guzarta hai. Uski equation likho.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Example 10.2NCERT Example 2 · p. 180

Centre aur radius diye hain

Us circle ki equation likho jiska centre (2,−5) aur radius 3 hai, phir use expand karo.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Example 10.3NCERT Example 3 · p. 180

Completing squares se circle padhna

Circle x2+y2−6x+4y−12=0 ka centre aur radius nikaalo.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Example 10.4NCERT Example 4 · p. 181

Do points aur centre ke liye ek line

Ek circle A(1,3) aur B(5,1) se guzarta hai, aur uska centre line x−2y=2 par hai. Circle nikaalo.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Quick check
3 mein se 1
Circle x2+y2−2x+6y−15=0 ka radius kya hai?
Answer dekho

Answer 5

Squares complete karo: (x−1)2+(y+3)2=15+1+9=25, isliye r=5. Answer 15 dene ka matlab hai squares complete karte waqt jode gaye 1 aur 9 ko bhool jaana.
Practice · 9 questions

Practice 10.1: answers ke saath

  1. Short answerEasyNCERT Exercise 10.1 Q1–Q4

    Har circle ki equation uske centre aur radius se expanded form mein likho.

    1. Centre (0,−3) aur radius 3

      Solution dikhao

      Answerx2+y2+6y=0

      x2+(y+3)2=9
      x2+y2+6y=0
    2. Centre (4,−1) aur radius 5

      Solution dikhao

      Answerx2+y2−8x+2y−8=0

      (x−4)2+(y+1)2=25
      x2+y2−8x+2y−8=0
    3. Centre (13,−12) aur radius 16

      Solution dikhao

      Answer3x2+3y2−2x+3y+1=0

      (x−13)2+(y+12)2=136

      Expand karo: x2+y2−23x+y+19+14−136=0, aur 19+14−136=13. 3 se multiply karo:

      3x2+3y2−2x+3y+1=0
    4. Centre (−2,−2) aur radius 2

      Solution dikhao

      Answerx2+y2+4x+4y+6=0

      (x+2)2+(y+2)2=2
      x2+y2+4x+4y+6=0
  2. Short answerMediumNCERT Exercise 10.1 Q5

    Centre (p,−q) aur radius p2+q2 wale circle ki equation nikaalo. Kaun sa special point hamesha is par hota hai?

    Solution dikhao

    Answerx2+y2−2px+2qy=0; yeh origin se guzarta hai.

    (x−p)2+(y+q)2=p2+q2
    x2+y2−2px+2qy=0

    Koi constant term nahi hai, isliye (0,0) equation ko satisfy karta hai: circle origin se guzarta hai. Yeh samajh mein aata hai, kyunki radius centre se origin tak ke distance ke barabar hai.

  3. Short answerEasyNCERT Exercise 10.1 Q6–Q9

    Har circle ka centre aur radius nikaalo.

    1. (x−7)2+(y+2)2=20

      Solution dikhao

      AnswerCentre (7,−2) aur radius 25

      (10.1) se seedha padho: h=7, k=−2, r=20=25.

    2. x2+y2+6x−10y−2=0

      Solution dikhao

      AnswerCentre (−3,5) aur radius 6

      Constant ko doosri side le jao aur 9 aur 25 jodo: 2+9+25=36.

      (x+3)2+(y−5)2=36
    3. x2+y2+2x−12y+12=0

      Solution dikhao

      AnswerCentre (−1,6) aur radius 5

      −12 mein 1 aur 36 jodo: right side 25 ban jaati hai.

      (x+1)2+(y−6)2=25
    4. 3x2+3y2+2y=0

      Solution dikhao

      AnswerCentre (0,−13) aur radius 13

      3 se divide karo: x2+y2+23y=0.

      x2+(y+13)2=19
  4. Long answerMediumNCERT Exercise 10.1 Q10–Q11

    Diye gaye do points se guzarne wala woh circle nikaalo jiska centre di gayi line par ho.

    1. (3,1) aur (−1,3) se hokar; centre 3x−y=2 par

      Solution dikhao

      Answer(x−2)2+(y−4)2=10

      (3−h)2+(1−k)2=(1+h)2+(3−k)2

      Yeh simplify hokar k=2h banta hai. 3h−k=2 ke saath: h=2, k=4, aur r2=12+32=10.

    2. (5,2) aur (−1,4) se hokar; centre x+y=9 par

      Solution dikhao

      Answer(x−3)2+(y−6)2=20

      (5−h)2+(2−k)2=(1+h)2+(4−k)2

      Yeh simplify hokar k=3h−3 banta hai. h+k=9 ke saath: h=3, k=6, aur r2=22+42=20.

  5. Short answerMediumNCERT Exercise 10.1 Q12

    Radius 13 wale ek circle ka centre y-axis par hai aur woh (5,1) se guzarta hai. Aise saare circles nikaalo.

    Solution dikhao

    Answerx2+(y−13)2=169 ya x2+(y+11)2=169

    25+(1−k)2=169

    To (1−k)2=144, jisse k=13 ya k=−11 milta hai. Dono circles sahi hain: x2+(y−13)2=169 aur x2+(y+11)2=169.

  6. Short answerMediumNCERT Exercise 10.1 Q13

    Ek circle origin se guzarta hai aur axes ko dobara A aur B par kaatta hai.

    1. Ise nikaalo jab A=(6,0) aur B=(0,−4) hon.

      Solution dikhao

      Answerx2+y2−6x+4y=0

      (0,0) se hokar: c=0. (6,0) se hokar: 36+12g=0, isliye g=−3. (0,−4) se hokar: 16−8f=0, isliye f=2.

      x2+y2−6x+4y=0
    2. Ise general case mein nikaalo jab A=(p,0) aur B=(0,q) hon.

      Solution dikhao

      Answerx2+y2−px−qy=0

      Wahi steps c=0, 2g=−p aur 2f=−q dete hain, isliye circle x2+y2−px−qy=0. hai. Angle AOB ek right angle hai, isliye AB ek diameter hai.

  7. Short answerEasyNCERT Exercise 10.1 Q14

    (−1,3) par centre wala ek circle (2,−1) se guzarta hai. Uski equation likho.

    Solution dikhao

    Answer(x+1)2+(y−3)2=25

    r2=32+42=25
    (x+1)2+(y−3)2=25
  8. Quick answerEasyNCERT Exercise 10.1 Q15

    Circle x2+y2=16 ke compare mein point (3.5,−2.5) kahan hai?

    Answer dekho

    Answer (C) bahar

    3.52+2.52=12.25+6.25=18.5>16, isliye point centre se 4 se zyada door hai: bahar.
  9. Quick answerMedium

    Circle x2+y2−8x+6y+k=0 ka radius 6 hai. k nikaalo.

    Answer dekho

    Answer -11

    Squares complete karne par (x−4)2+(y+3)2=25−k. 25−k=36 rakhne par k=−11 milta hai.

10.4 Parabola

Boundary ki taraf uchhali gayi cricket ball, garden hose se nikalti paani ki dhaar, suspension bridge ka cable: har ek (lagbhag) ek hi tarah ka curve follow karta hai. Iske geometric description ke liye ek point aur ek line chahiye.

Definition
Parabola

Ek line l aur uske bahar ek point F lo, dono ek hi plane mein. Parabola us plane ke un points se banta hai jinka F se distance unke l se distance ke barabar ho. Line l directrix hai aur F focus hai.

To ek point P parabola par tab hai jab focus F se uska distance PF, directrix se uske distance PM ke barabar ho, jahan M point P se daale gaye perpendicular ka foot hai (Fig. 10.6).

4/4Yeh ek parabola par padte hain; iska axis F se guzarta hai.

Fig. 10.6Parabola ka har point focus se utna hi door hai jitna directrix se.NCERT Figs 10.13, 10.14 · p. 182

Neeche ke paas ek horizontal dashed directrix aur uske beech ke upar ek focus F. Step 1 mein sirf focus aur directrix hain. Step 2 ek point P jodta hai, jisse F tak ek solid segment aur directrix par M tak ek dashed vertical segment hai, aur dono barabar hain: PF = PM. Step 3 teen aur points jodta hai, har ek ke saath barabar segments ka apna pair. Step 4 in sab se guzarta parabola banata hai, jismein F se guzarta vertical axis hai aur vertex focus aur directrix ke theek beech mein hai.

Focus se guzarne wali aur directrix ke perpendicular line parabola ka axis hai, aur curve iske around symmetric hai. Axis parabola se ek hi point par milta hai, jo vertex hai, aur yeh focus aur directrix ke theek beech mein hota hai.

10.4.1 Parabola ki standard equations

Sabse simple equations tab milti hain jab vertex origin par ho aur axis ek coordinate axis ke saath line up ho. Phir bhi parabola chaar taraf face kar sakta hai: right, left, upar ya neeche. Hum pehli derive karte hain aur baaki symmetry se nikaalte hain.

DerivationRight ki taraf khulne wala parabola

Focus F(a,0) lo jahan a>0, aur directrix x=−a; tab dono ke beech ka vertex origin hai. Kisi bhi point P(x,y) ke liye directrix par perpendicular ka foot M(−a,y) hai, isliye PM=∣x+a∣ aur PF=(x−a)2+y2.

P parabola par tabhi hai jab PF=PM. Dono sides non-negative hain, isliye hum bina koi point jode ya khoye square kar sakte hain: PF2=PM2. (x−a)2 ko doosri side le jaane par y2 akela bachta hai:

y2=(x+a)2−(x−a)2=4ax
Standard parabola
y2=4ax,a>0
(10.3)

Ulta, agar y2=4ax hai to x≥0 aur PF2=(x−a)2+4ax=(x+a)2, isliye PF=x+a=PM. Parabola ka har point (10.3) ko satisfy karta hai, aur (10.3) ka har solution parabola par hai.

y2=4ax ke kisi bhi point ka x negative nahi hota, kyunki left side kabhi negative nahi ho sakti jab 4a positive hai. Right ki taraf koi limit nahi hai: y=±2ax badhta hi rehta hai, isliye arms quadrants I aur IV mein hamesha ke liye khulte jaate hain, aur positive x-axis mein ek doosre ki mirror images hain.

1/4y2=4ax right ki taraf khulta hai.

Fig. 10.7Pehle parabola ko reflect karne se baaki teen standard forms milte hain.NCERT Fig. 10.15 · p. 182

Axes ka ek set. Step 1: parabola y squared equals 4ax right ki taraf khulta hai, focus F(a, 0) aur vertical directrix x = minus a ke saath. Step 2: y squared equals minus 4ax left ki taraf khulta hai, focus F(minus a, 0), directrix x = a. Step 3: x squared equals 4ay upar ki taraf khulta hai, focus F(0, a), horizontal directrix y = minus a. Step 4: x squared equals minus 4ay neeche ki taraf khulta hai, focus F(0, minus a), directrix y = a. Har step mein vertex origin par hai.

x ki jagah −x rakhne se curve y-axis mein reflect hota hai; x aur y ko aapas mein badalne se yeh line y=x mein reflect hota hai. Yeh moves (10.3) ko baaki teen standard forms mein badal dete hain (Table 10.1).

Table 10.1Chaar standard parabolas (a>0, vertex origin par)
EquationFocusDirectrixKidhar khulta hai
y2=4ax(a,0)x=−aright ki taraf
y2=−4ax(−a,0)x=aleft ki taraf
x2=4ay(0,a)y=−aupar
x2=−4ay(0,−a)y=aneeche

10.4.2 Latus rectum

Definition
Latus rectum

Kisi conic ka latus rectum focus se guzarne wali woh chord hai jo axis ke perpendicular ho (ellipse ke liye major axis; hyperbola ke liye transverse axis), aur jiske dono ends curve par hon.

y2=4ax ke liye latus rectum line x=a par hota hai. x=a rakhne par y2=4a2 milta hai, isliye iske ends L(a,2a) aur L′(a,−2a) hain. Picture se bhi ek proof hai (Fig. 10.8): L parabola par hai, isliye LF, L se directrix tak ke distance ke barabar hai, jo lines x=−a aur x=a ke beech ka gap 2a hai.

3/3To LL′=2a+2a=4a.

Fig. 10.8Latus rectum ka har half focus se directrix tak ke gap 2a jitna lamba hai.NCERT Fig. 10.18 · p. 185

Vertex O, focus F aur vertical dashed directrix wala right ki taraf khulta parabola. Step 1 F se guzarti, axis ke perpendicular chord LL prime banata hai. Step 2 L se directrix tak ek dashed horizontal segment jodta hai aur use 2a mark karta hai; segment LF bhi 2a hai, kyunki L parabola par hai. Step 3 L prime F ko bhi 2a mark karta hai aur poori chord LL prime ko 4a likhta hai.

y² = 4ax ka latus rectum
LL′=4a
(10.4)
Example 10.5NCERT Example 5 · p. 185

Parabola ko padhna

Parabola x2=−12y ka axis batao aur uska focus, directrix aur latus rectum ki length nikaalo.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Example 10.6NCERT Example 6 · p. 186

Focus aur directrix diye hain

Us parabola ki equation likho jiska focus (0,4) aur directrix y=−4 hai.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Example 10.7NCERT Example 7 · p. 186

Vertex aur focus diye hain

Ek parabola ka vertex (0,0) par aur focus (−52,0) par hai. Uski equation nikaalo.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Example 10.8NCERT Example 8 · p. 186

Diye gaye point se hokar

Ek parabola ka vertex origin par hai, axis x-axis ke saath hai, aur yeh (3,−6) se guzarta hai. Uski equation nikaalo.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Quick check
4 mein se 1
Parabola x2=−8y ka focus hai
Answer dekho

Answer (C) (0,−2)

Yahan 4a=8, isliye a=2; parabola neeche ki taraf khulta hai, isliye focus (0,−2) hai. (0,−8) chunne ka matlab hai a ki jagah 4a use karna.
Practice · 6 questions

Practice 10.2: answers ke saath

  1. Short answerEasyNCERT Exercise 10.2 Q1–Q6

    Har parabola ke liye axis, focus, directrix aur latus rectum ki length batao.

    1. y2=16x

      Solution dikhao

      AnswerFocus (4,0); axis x-axis; directrix x=−4; latus rectum 16

      4a=16, a=4; right ki taraf khulta hai. Focus (4,0), axis x-axis, directrix x=−4, latus rectum 16.

    2. x2=−10y

      Solution dikhao

      AnswerFocus (0,−52); axis y-axis; directrix y=52; latus rectum 10

      4a=10, a=52; neeche khulta hai. Focus (0,−52), axis y-axis, directrix y=52, latus rectum 10.

    3. y2=−6x

      Solution dikhao

      AnswerFocus (−32,0); axis x-axis; directrix x=32; latus rectum 6

      4a=6, a=32; left ki taraf khulta hai. Focus (−32,0), axis x-axis, directrix x=32, latus rectum 6.

    4. x2=20y

      Solution dikhao

      AnswerFocus (0,5); axis y-axis; directrix y=−5; latus rectum 20

      4a=20, a=5; upar khulta hai. Focus (0,5), axis y-axis, directrix y=−5, latus rectum 20.

  2. Short answerEasyNCERT Exercise 10.2 Q7–Q8

    Diye gaye focus aur directrix wale parabola ki equation nikaalo.

    1. Focus (0,7) aur directrix y=−7

      Solution dikhao

      Answerx2=28y

      Vertex origin hai aur focus uske upar hai: x2=4ay jahan a=7, isliye x2=28y.

    2. Focus (−4,0) aur directrix x=4

      Solution dikhao

      Answery2=−16x

      Vertex origin hai aur focus uske left mein hai: y2=−4ax jahan a=4, isliye y2=−16x.

  3. Short answerEasyNCERT Exercise 10.2 Q9–Q10

    Vertex origin par hai. Diye gaye focus se parabola ki equation likho.

    1. Focus (0,−1)

      Solution dikhao

      Answerx2=−4y

      a=1 ke saath neeche khulta hai: x2=−4y.

    2. Focus (72,0)

      Solution dikhao

      Answery2=14x

      a=72 ke saath right ki taraf khulta hai: y2=4⋅72 x=14x.

  4. Short answerMediumNCERT Exercise 10.2 Q11–Q12

    Vertex origin par hai. Diye gaye axis aur point se parabola nikaalo.

    1. Axis x-axis ke saath; (−3,6) se guzarta hai

      Solution dikhao

      Answery2=−12x

      36=k(−3)⇒k=−12

      To y2=−12x, jo left ki taraf khulta hai, jaisa negative x wale point ke liye zaroori hai.

    2. y-axis ke around symmetric; (6,−4) se guzarta hai

      Solution dikhao

      Answerx2=−9y

      36=k(−4)⇒k=−9

      To x2=−9y, jo neeche ki taraf khulta hai.

  5. Quick answerMedium

    Parabola 3y2=8x ke focus ka x-coordinate kya hai?

    Answer dekho

    Answer 0.6667

    3 se divide karo: y2=83x, isliye 4a=83 aur a=23≈0.667. Focus (23,0) hai.
  6. Quick answerMedium

    Parabola y2=4ax point (2,−4) se guzarta hai. Uske latus rectum ki length hai

    Answer dekho

    Answer (C) 8

    16=8a se a=2 milta hai, isliye latus rectum 4a=8 hai. Option 2 khud a hai.

10.5 Ellipse

Har planet Sun ke around ek ellipse par chalta hai, aur Sun centre par nahi balki focus naam ke ek special point par hota hai. Yeh Kepler ka first law hai, jo 1609 mein publish hua. Earth ke liye ellipse itna gol hai ki aankh se tum use circle se alag nahi pehchaan paoge.

Definition
Ellipse

Ek plane mein do fixed points F1 aur F2 lo. Ellipse us plane ke un points P se banta hai jinke liye sum PF1+PF2 ki value ek hi rehti hai. F1 aur F2 iske foci hain (singular: focus).

1/4Yahan PF1 lamba aur PF2 chhota hai; dono ka total 2a hai.

Fig. 10.9P kaise bhi move kare, PF1+PF2 same rehta hai: isi se curve ellipse banta hai.NCERT Figs 10.20, 10.21 · p. 187

Ek horizontal line par do foci F1 aur F2. Ek point P, F1 se solid segment aur F2 se dashed segment se juda hai. Drawing ke neeche ek bar do pieces PF1 aur PF2 mein bata hai, jo ek ke baad ek rakhe hain. Steps 1 se 3 P ko curve par teen positions par le jaate hain aur har baar curve ka aur hissa banta hai; aakhri position minor axis ke neeche wale end par hai jahan dono pieces barabar hain; bar ka split khisakta hai lekin uski total length kabhi nahi badalti. Step 4 centre O, do vertices, foci se guzarte major axis aur O se guzarte minor axis ke saath poora ellipse banata hai, aur batata hai ki bar ki length 2a major axis ki length ke barabar hai.

Kuch points aur lengths kisi bhi ellipse ko describe kar dete hain. Foci ke theek beech mein centre hai. Sabse lambi chord, major axis, dono foci se guzarti hai, aur iske ends do vertices hain. Centre se iske square chhoti minor axis chalti hai. Inki lengths 2a aur 2b kehlati hain, aur foci 2c ki doori par hain; isliye semi-axes a aur b hain, aur har focus centre se c door hai.

10.5.1 a, b aur c aapas mein kaise jude hain

Pehli baat, constant sum major axis ki length hai. F2 ke aage wale vertex A par AF2=a−c aur AF1=a+c, jo milkar 2a banate hain. Sum har point par same hai, isliye ellipse ke har point P ke liye PF1+PF2=2a.

2/4BF1=BF2=a, isliye a2=b2+c2.

Fig. 10.10x2a2+y2b2=1 ke vertices, foci, latus rectum aur bounding box.NCERT Figs 10.22, 10.23 · p. 188

Origin par centre wala ek ellipse jiska major axis x-axis ke saath hai. Step 1 vertices (a, 0) aur (minus a, 0) aur minor axis ke ends (0, b) aur (0, minus b) mark karta hai. Step 2 foci F1 aur F2 jodta hai aur upar wale point B ko dono se jodta hai; har segment a hai, aur legs b aur c aur hypotenuse a wala right triangle a squared equals b squared plus c squared deta hai. Step 3 F2 se guzarta latus rectum banata hai, jo b squared over a length ke do halves se bana hai. Step 4 lines x = plus ya minus a aur y = plus ya minus b ke beech ke rectangle ko shade karta hai, jise ellipse chhoota hai lekin kabhi bahar nahi jaata.

Ab minor axis ka ek end B lo. Yeh F1F2 ke perpendicular bisector par hai, isliye BF1=BF2, aur kyunki dono milkar 2a hain, har ek a ke barabar hai. B, centre aur F2 se bane right triangle ke legs b aur c hain aur hypotenuse a hai (Fig. 10.10 ka step 2):

Ellipse
a2=b2+c2
(10.5)

Khaas taur par c=a2−b2 aur b<a: major axis sach mein lambi wali hai.

10.5.2 Eccentricity

Definition
Eccentricity

Ellipse ya hyperbola ki eccentricity e=ca hai: centre se focus tak ka distance divided by centre se vertex tak ka distance.

Ellipse ke liye 0≤c<a, isliye 0≤e<1, aur har focus centre se c=ae door hai. Eccentricity naapti hai ki ellipse gol hone se kitna door hai. a ko fixed rakho aur e badhao: foci vertices ki taraf khisakte hain aur ellipse flat hota jaata hai, kyunki b=a1−e2 (Fig. 10.11). e=0 par dono foci centre par hote hain aur ellipse radius a ka circle hai.

3/4Zyada flat: b=0.6a.

Fig. 10.11Same a, badhta e: foci bahar khisakte hain aur ellipse flat hota hai.NCERT 10.5.2 · p. 188

Axes par bana fixed semi-major axis a wala ek ellipse, dono foci mark kiye hue aur ek side panel jo e aur b batata hai. Step 1: e = 0, foci centre par saath hain aur curve b = a wala circle hai. Step 2: e = 0.6, foci alag hote hain aur b = 0.8a. Step 3: e = 0.8, b = 0.6a aur ellipse zyada flat hai. Step 4: e = 0.95, foci vertices ke paas hain aur b lagbhag 0.31a hai, ek bahut flat ellipse.

10.5.3 Ellipse ki standard equations

Centre ko origin par rakho aur foci F1(−c,0) aur F2(c,0) ko x-axis par. Ek point P(x,y) ellipse par tabhi hai jab PF1+PF2=2a, jahan a>c.

DerivationSum rule se ellipse ki equation

Do square roots ke sum ko square karne ki jagah unke squares ka difference dekho. y2 wale terms cancel ho jaate hain:

PF12−PF22=(x+c)2−(x−c)2=4cx

PF1+PF2=2a se divide karne par PF1−PF2=2cxa milta hai. Ise PF1+PF2=2a mein jodne aur ghatane se har distance alag se milta hai:

Focal distances
PF1=a+caxPF2=a−cax
(10.6)

Ab doosre ko square karo, PF22=(x−c)2+y2 use karke; dono sides ke −2cx terms cancel ho jaate hain:

x2+c2+y2=a2+c2a2x2a2−c2a2 x2+y2=a2−c2

b2=a2−c2 likho, jo positive hai kyunki a>c, aur b2 se divide karo:

Standard ellipse (a > b)
x2a2+y2b2=1
(10.7)

Ulta, maano (x,y) (10.7) ko satisfy karta hai. Tab y2=b2(1−x2a2), aur expand karne par PF12=(x+c)2+y2=(a+cax)2. milta hai. Kyunki ∣x∣≤a aur c<a, bracket positive hai, isliye PF1=a+cax. Isi tarah PF2=a−cax. Dono milkar 2a hote hain, isliye point ellipse par hai.

Ellipse kahan tak pahunchta hai? (10.7) ke left wale do terms kabhi negative nahi hote aur milkar 1 hote hain, isliye koi bhi 1 se zyada nahi ho sakta. Isliye x2≤a2 aur y2≤b2: curve lines x=±a aur y=±b ke box mein band hai, aur har line ko ek vertex ya minor axis ke ek end par chhoota hai (Fig. 10.10 ka step 4).

x aur y ke roles badal do to khada ellipse milta hai, jiske foci (0,±c) hain: x2b2+y2a2=1. Yahi pair ellipse ki standard equations kehlata hai; shift ya tilt kiye gaye ellipse ke liye lambi equation chahiye, jo aage ki classes mein aayegi.

SimulationEllipse ki talaash

Dono axes par minus 6 se 6 tak ek coordinate grid, jismein do fixed foci hain, F1 (minus 4, 0) par aur F2 (4, 0) par, aur ek draggable point P jo (2, 2) se shuru hota hai. P se har focus tak ke distances bane hain aur naape jaate hain, aur P 0.1 ke steps par snap hota hai aur apne coordinates dikhata hai.

Fig. 10.12P ko drag karo aur dono distances jodo. Ellipse x225+y29=1 woh saare points hain jahan inka total 10 hai.
Try karo
  • P ko (5,0) par aur phir (0,3) par le jao. Check karo ki dono jagah PF1+PF2=10 hai.
  • (4,1.8) try karo, jo ek latus rectum ka end hai, aur (−3,2.4) bhi. Kya total ab bhi 10 hai?
  • P ko (3,2) par rakho. Total 10 se zyada hai ya kam? P ellipse ke andar hai ya bahar?

10.5.4 Latus rectum

F2(c,0) se guzarta latus rectum line x=c par hai. (10.7) mein substitute karke aur a2−c2=b2 use karke:

y2b2=1−c2a2=b2a2

isliye y=±b2a aur ends (c,±b2a) hain. Latus rectum is height ka do guna hai:

Ellipse aur hyperbola
latus rectum=2b2a
(10.8)
Example 10.9NCERT Example 9 · p. 192

Ek ellipse ke baare mein sab kuch

Ellipse x2289+y264=1 ke foci aur vertices, dono axes ki lengths, eccentricity aur latus rectum batao.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Example 10.10NCERT Example 10 · p. 193

Khada hua ellipse

Ellipse 4x2+y2=16 ko poora describe karo: foci, vertices, axis lengths, eccentricity aur latus rectum.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Example 10.11NCERT Example 11 · p. 193

Vertices aur foci se

Vertices (0,±15) aur foci (0,±9) wala ellipse nikaalo.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Example 10.12NCERT Example 12 · p. 194

Major axis aur foci se

Ek ellipse ki major axis ki length 14 hai aur uske foci (±26,0) hain. Uski equation nikaalo.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Example 10.13NCERT Example 13 · p. 194

Do points se hokar

Standard form wale ek ellipse ki major axis x-axis ke saath hai aur yeh (2,2) aur (−3,1) se guzarta hai. Uski equation nikaalo.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Quick check
4 mein se 1
Ellipse x216+y225=1 ke foci hain
Answer dekho

Answer (D) (0,±3)

Bada denominator, 25, y2 ke neeche hai, isliye major axis y-axis hai, a=5, b=4 aur c=25−16=3: foci (0,±3). Denominators jodne se 41 milta hai, jo hyperbola ka rule hai aur yahan galat hai.
Practice · 9 questions

Practice 10.3: answers ke saath

  1. Long answerEasyNCERT Exercise 10.3 Q1–Q6

    Har ellipse ke foci, vertices, major aur minor axes ki lengths, eccentricity aur latus rectum nikaalo.

    1. x249+y224=1

      Solution dikhao

      AnswerFoci (±5,0), vertices (±7,0); axes 14 aur 46; e=57; latus rectum 487

      a=7, b=26, x-axis ke saath.

      c=49−24=5

      Isliye e=57 aur latus rectum 2⋅247=487. hai.

    2. x220+y236=1

      Solution dikhao

      AnswerFoci (0,±4), vertices (0,±6); axes 12 aur 45; e=23; latus rectum 203

      a=6, y-axis ke saath, b=25.

      c=36−20=4

      Isliye e=46=23 aur latus rectum 406=203. hai.

    3. x212+y216=1

      Solution dikhao

      AnswerFoci (0,±2), vertices (0,±4); axes 8 aur 43; e=12; latus rectum 6

      a=4, y-axis ke saath, b=23.

      c=16−12=2

      Isliye e=12 aur latus rectum 244=6. hai.

  2. Long answerMediumNCERT Exercise 10.3 Q7–Q9

    Har ellipse ko standard form mein likho, phir uske foci, vertices, axes, eccentricity aur latus rectum nikaalo.

    1. 16x2+25y2=400

      Solution dikhao

      Answerx225+y216=1: foci (±3,0), vertices (±5,0); axes 10 aur 8; e=35; latus rectum 325

      x225+y216=1

      a=5, b=4, c=3, x-axis ke saath, isliye e=35 aur latus rectum 325. hai.

    2. x2+4y2=4

      Solution dikhao

      Answerx24+y2=1: foci (±3,0), vertices (±2,0); axes 4 aur 2; e=32; latus rectum 1

      x24+y21=1

      a=2, b=1, c=3, isliye e=32 aur latus rectum 2⋅12=1. hai.

    3. 9x2+5y2=45

      Solution dikhao

      Answerx25+y29=1: foci (0,±2), vertices (0,±3); axes 6 aur 25; e=23; latus rectum 103

      x25+y29=1

      a=3, y-axis ke saath, b=5, c=2, isliye e=23 aur latus rectum 103. hai.

  3. Short answerEasyNCERT Exercise 10.3 Q10–Q12

    Diye gaye vertices aur foci wala ellipse nikaalo.

    1. Vertices (±10,0) aur foci (±6,0)

      Solution dikhao

      Answerx2100+y264=1

      b2=100−36=64
    2. Vertices (0,±7) aur foci (0,±13)

      Solution dikhao

      Answerx236+y249=1

      b2=49−13=36

      Major axis y-axis hai, isliye a2=49 y2 ke neeche aata hai.

    3. Vertices (±9,0) aur foci (±5,0)

      Solution dikhao

      Answerx281+y256=1

      b2=81−25=56
  4. Short answerEasyNCERT Exercise 10.3 Q13–Q14

    Axes ke ends se ellipse nikaalo.

    1. Major axis ke ends (±7,0); minor axis ke ends (0,±2)

      Solution dikhao

      Answerx249+y24=1

      a=7 x-axis par aur b=2.

    2. Major axis ke ends (0,±10); minor axis ke ends (±2,0)

      Solution dikhao

      Answerx24+y210=1

      a2=10 y2 ke neeche aur b2=4 x2 ke neeche.

  5. Short answerMediumNCERT Exercise 10.3 Q15–Q16

    Ek axis ki length aur foci se ellipse nikaalo.

    1. Major axis ki length 18; foci (±4,0)

      Solution dikhao

      Answerx281+y265=1

      a=9 aur c=4.

      b2=81−16=65
    2. Minor axis ki length 10; foci (0,±12)

      Solution dikhao

      Answerx225+y2169=1

      b=5, c=12, major axis y-axis ke saath.

      a2=25+144=169
  6. Short answerMediumNCERT Exercise 10.3 Q17–Q18

    Diye gaye data se origin par centre wala ellipse nikaalo.

    1. Foci (0,±5) aur a=6

      Solution dikhao

      Answerx211+y236=1

      b2=36−25=11

      Foci y-axis par hain, isliye a2=36 y2 ke neeche aata hai.

    2. b=2, c=3, foci x-axis par

      Solution dikhao

      Answerx213+y24=1

      a2=4+9=13
  7. Long answerHardNCERT Exercise 10.3 Q19–Q20

    Diye gaye do points se guzarta standard ellipse nikaalo.

    1. Centre origin par, major axis y-axis par, (2,3) aur (1,5) se hokar

      Solution dikhao

      Answer16x2+3y2=91

      4A+9B=1,A+25B=1

      Tab A=1−25B, isliye 4−91B=1: B=391 aur A=1691. Yahan 1B=913>1A=9116, isliye major axis sach mein vertical hai.

      16x2+3y2=91
    2. Major axis x-axis par, (3,2) aur (−1,3) se hokar

      Solution dikhao

      Answer5x2+8y2=77

      9A+4B=1,A+9B=1

      Tab A=1−9B, isliye 9−77B=1: B=877 aur A=577, aur jaisa chahiye 1A>1B.

      5x2+8y2=77
  8. Quick answerMedium

    Ek ellipse ki minor axis uske foci ke beech ke distance jitni lambi hai. Uski eccentricity hai

    Answer dekho

    Answer (B) 12

    2b=2c se b=c milta hai, isliye a2=2c2 aur e=ca=12. Option 2 1 se zyada hai, jo ellipse ke liye impossible hai.
  9. Quick answerMedium

    Assertion (A): Ellipse x29+y216=1 ke foci y-axis par hain. Reason (R): Standard ellipse ki major axis bade denominator wale variable ke saath hoti hai, aur foci major axis par hote hain.

    Answer dekho

    Answer (A) A aur R dono true hain, aur R, A ko explain karta hai

    Yahan 16>9, isliye major axis y-axis hai aur foci (0,±7) hain. R hi theek iska reason hai.

10.6 Hyperbola

Ek doosre se bahut door do radio stations ek hi pal mein ek pulse bhejte hain. Ek ship ko ek pulse doosre se 0.2 ms pehle sunai deti hai. Radio ek millisecond mein 300 km chalta hai, isliye ship pehle station se doosre ke mukable 60 km zyada paas hai. Distances ke isi difference wale saare points ek curve par hain, jo hyperbola hai; stations ka doosra pair ek doosra curve deta hai, aur ship wahan hai jahan dono kaatte hain. LORAN jaise navigation systems isi tarah kaam karte the.

Definition
Hyperbola

Ek plane mein do fixed points F1 aur F2 lo. Hyperbola us plane ke un points P se banta hai jinke liye PF1 aur PF2 ka difference, yaani bada minus chhota, ek hi value rakhta hai. F1 aur F2 iske foci hain.

1/4F2 ke paas: PF1−PF2=2a.

Fig. 10.13Dono branches ke har point par bada distance minus chhota distance same rehta hai, yaani 2a.NCERT Figs 10.27, 10.28 · p. 196

Ek horizontal line par do foci F1 aur F2, curve ki halki outline ke saath. Ek point P, F1 se solid segment aur F2 se dashed segment se juda hai, aur neeche do bars PF1 aur PF2 dikhate hain, jahan lambe bar ki extra length box mein hai aur uspar 2a likha hai. Steps 1 aur 2 P ko right branch par do jagah rakhte hain, F2 ke paas, doosri jagah vertex ke kareeb; bars badalte hain lekin box wala difference 2a hi rehta hai. Step 3 P ko left branch par rakhta hai, F1 ke paas, jahan ab PF2 lamba bar hai, phir se 2a zyada lamba. Step 4 dono branches ko centre, do vertices A aur A prime, foci se guzarte transverse axis aur vertical conjugate axis ke saath banata hai.

Socho ki dono branches ek doosre ki taraf face kar rahi hain. Har branch ka woh point jo doosri ke sabse paas hai vertex hai, aur vertices 2a ki doori par hain. Inse guzarne wali line dono foci se bhi guzarti hai, jo aur bahar 2c ki doori par hain; yeh line transverse axis hai, aur F1F2 ka midpoint centre hai. Centre se iske right angle par guzarne wali line conjugate axis hai.

Kyunki vertices foci ke beech hain, c>a, aur number b=c2−a2 real hai. Conjugate axis par centre ke around 2b length ka segment bhi conjugate axis kehlata hai; Fig. 10.15 dikhata hai ki b kya naapta hai.

Constant difference phir se 2a hai. Dono foci ko aapas mein badalne se “bada minus chhota” nahi badalta, isliye hyperbola apne conjugate axis ke around symmetric hai, aur uske vertices mirror images hain, har ek centre se a door. F2 ke paas wale vertex A par AF1=c+a aur AF2=c−a, jinka fark 2a hai. Isliye hyperbola ke har point P par ∣PF1−PF2∣=2a.

SimulationConstant difference

Dono axes par minus 8 se 8 tak ek coordinate grid, jismein do fixed foci hain, F1 (minus 4, 0) par aur F2 (4, 0) par, aur ek draggable point P jo (6, 3) se shuru hota hai. P se har focus tak ke distances bane hain aur naape jaate hain, aur P grid points par snap hota hai aur apne coordinates dikhata hai.

Fig. 10.14P ko drag karo aur bade distance mein se chhota ghatao. Hyperbola x24−y212=1 woh saare points hain jahan difference 4 hai.
Try karo
  • P ko (2,0) par le jao, jo ek vertex hai. Check karo ki distances mein 4 ka fark hai.
  • x=±4 wale woh chaar grid points dhoondho jahan difference 4 hai. (Hint: y=±6 try karo.)
  • P ko y-axis par rakho. Wahan difference kya hai, aur hyperbola ka koi point us axis par kyun nahi hai?

10.6.1 Eccentricity

Ratio e=ca hyperbola ke liye bhi defined hai. Ab foci vertices ke aage hain, c>a, isliye e>1, aur har focus ab bhi centre se ae door hai. Bada e matlab chaudi branches, kyunki ba=e2−1.

10.6.2 Hyperbola ki standard equation

Centre ko origin par aur foci ko F1(−c,0) aur F2(c,0) par rakho. Right branch par ek point P(x,y) lo, jo F2 ke paas wali hai, taaki PF1−PF2=2a.

DerivationDifference rule se hyperbola ki equation

Ellipse wala trick yahan bhi kaam karta hai. Squares ka difference ab bhi PF12−PF22=4cx hai; ise PF1−PF2=2a se divide karo:

PF1+PF2=2cxa

PF1−PF2=2a ke saath milkar yeh do focal distances deta hai:

Right branch
PF1=cax+aPF2=cax−a
(10.9)

Doosre ko square karo, PF22=(x−c)2+y2 ke saath; ek baar phir −2cx terms cancel ho jaate hain:

x2+c2+y2=c2a2x2+a2c2−a2a2 x2−y2=c2−a2

b2=c2−a2 ke saath, b2 se divide karo:

Standard hyperbola
x2a2−y2b2=1
(10.10)

Left branch par, jahan PF2−PF1=2a, dono focal distances ka sign badal jaata hai lekin unke squares ka nahi, isliye wahi equation milti hai.

Ulta, agar (x,y) (10.10) ko satisfy karta hai, to y2=b2(x2a2−1) aur expand karne par PF12=(cax+a)2 aur PF22=(cax−a)2. milte hain. x≥a ke liye dono brackets positive hain, isliye PF1−PF2=2a; x≤−a ke liye dono negative hain, isliye PF2−PF1=2a. Dono hi case mein point hyperbola par hai.

(10.10) ko x2a2=1+y2b2 ki tarah padho: right side kam se kam 1 hai, isliye ∣x∣ kabhi a se neeche nahi ja sakta. Isliye vertical strip −a<x<a khaali hai (Fig. 10.15). Branches iske bahar rehti hain, y-axis ko kabhi nahi chhooti, aur bina ruke failti jaati hain.

2/4Foci vertices ke bahar hain, aur c2=a2+b2.

Fig. 10.15x2a2−y2b2=1 ke parts.NCERT Fig. 10.29 · p. 197

Coordinate axes par hyperbola x squared over a squared minus y squared over b squared equals 1. Step 1 vertices (a, 0) aur (minus a, 0) mark karta hai aur x = minus a aur x = a ke beech ki strip ko shade karta hai, jismein curve ka koi point nahi hai. Step 2 vertices ke bahar foci F1 aur F2 jodta hai, aur axes ke saath legs a aur b wala ek right triangle, jiska hypotenuse vertex se point (0, b) tak hai aur uski length c hai, isliye c squared equals a squared plus b squared. Step 3 vertices ke beech 2a length ke transverse axis aur y-axis ke saath 2b length ke conjugate axis ko highlight karta hai. Step 4 F2 se guzarta latus rectum banata hai, jo b squared over a length ke do halves se bana hai.

Hyperbola
c2=a2+b2
(10.11)

Foci y-axis par hon to standard equation y2a2−x2b2=1. hai. Jab a=b ho to hyperbola equilateral kehlata hai: x2−y2=a2, jahan c=a2. Aise hyperbolas bhi hote hain jinke axes koi aur perpendicular lines hon; woh aage ki classes mein aate hain.

10.6.3 Latus rectum

(10.10) mein x=c rakho: y2b2=c2a2−1=b2a2, isliye y=±b2a. Isliye hyperbola ke latus rectum ki length bhi ellipse jitni hi hai, 2b2a, jo (10.8) deta hai.

Table 10.2Ellipse aur hyperbola ki tulna (dono ka centre O par, foci x-axis par)
EllipseHyperbola
Rulesum 2a haidifference 2a hai
Equationx2a2+y2b2=1x2a2−y2b2=1
c2a2−b2a2+b2
e1 se kam1 se zyada
Vertices(±a,0)(±a,0)
Foci(±c,0)(±c,0)
Axesmajor 2a, minor 2btransverse 2a, conjugate 2b
Latus rectum2b2a2b2a
Example 10.14NCERT Example 14 · p. 200

Do hyperbolas ko padhna

(i) x2144−y225=1 aur (ii) 4y2−x2=4 ke foci, vertices, eccentricity aur latus rectum nikaalo.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Example 10.15NCERT Example 15 · p. 201

Foci aur vertices se

Foci (±4,0) aur vertices (±7,0) wala hyperbola nikaalo.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Example 10.16NCERT Example 16 · p. 201

Foci aur latus rectum se

Foci (±10,0) wala woh hyperbola nikaalo jiske latus rectum ki length 9 hai.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Quick check
4 mein se 1
Hyperbola y29−x216=1 ke foci hain
Answer dekho

Answer (A) (0,±5)

Positive term y mein hai, isliye foci y-axis par hain, aur c=9+16=5. 7 ghatane se aata hai, jo ellipse ka rule hai; (0,±3) vertices hain.
Practice · 9 questions

Practice 10.4: answers ke saath

  1. Short answerEasyNCERT Exercise 10.4 Q1–Q2

    Har hyperbola ke foci, vertices, eccentricity aur latus rectum nikaalo.

    1. x225−y2144=1

      Solution dikhao

      AnswerFoci (±13,0), vertices (±5,0), e=135, aur latus rectum 2885

      a=5 aur b=12.

      c=25+144=13

      Isliye e=135 aur latus rectum 2⋅1445=2885. hai.

    2. y216−x220=1

      Solution dikhao

      AnswerFoci (0,±6), vertices (0,±4), e=32, aur latus rectum 10

      a=4, y-axis ke saath, b2=20.

      c=16+20=6

      Isliye e=64=32 aur latus rectum 404=10. hai.

  2. Long answerMediumNCERT Exercise 10.4 Q3–Q6

    Har hyperbola ko standard form mein likho aur uske foci, vertices, eccentricity aur latus rectum nikaalo.

    1. 4x2−9y2=36

      Solution dikhao

      Answerx29−y24=1: foci (±13,0), vertices (±3,0), e=133, aur latus rectum 83

      a=3, b=2, c=13; aur latus rectum 2⋅43=83.

    2. 16y2−9x2=144

      Solution dikhao

      Answery29−x216=1: foci (0,±5), vertices (0,±3), e=53, aur latus rectum 323

      a=3, y-axis ke saath, b=4, c=5; latus rectum 323.

    3. 3x2−y2=12

      Solution dikhao

      Answerx24−y212=1: foci (±4,0), vertices (±2,0), e=2, aur latus rectum 12

      a=2, b2=12, c=16=4; aur latus rectum 242=12.

    4. 7y2−9x2=63

      Solution dikhao

      Answery29−x27=1: foci (0,±4), vertices (0,±3), e=43, aur latus rectum 143

      a=3, y-axis ke saath, b2=7, c=4; latus rectum 143.

  3. Short answerEasyNCERT Exercise 10.4 Q7–Q9

    Diye gaye vertices aur foci wala hyperbola nikaalo.

    1. Vertices (±6,0) aur foci (±10,0)

      Solution dikhao

      Answerx236−y264=1

      b2=100−36=64
    2. Vertices (0,±2) aur foci (0,±3)

      Solution dikhao

      Answery24−x25=1

      b2=9−4=5
    3. Vertices (0,±12) aur foci (0,±13)

      Solution dikhao

      Answery2144−x225=1

      b2=169−144=25
  4. Short answerMediumNCERT Exercise 10.4 Q10–Q11

    Foci aur ek axis ki length se hyperbola nikaalo.

    1. Foci (±7,0); transverse axis ki length 10

      Solution dikhao

      Answerx225−y224=1

      a=5 aur c=7.

      b2=49−25=24
    2. Foci (0,±10); conjugate axis ki length 12

      Solution dikhao

      Answery264−x236=1

      b=6 aur c=10.

      a2=100−36=64
  5. Long answerHardNCERT Exercise 10.4 Q12–Q13

    Foci aur latus rectum ki length se hyperbola nikaalo.

    1. Foci (±27,0) aur latus rectum 6

      Solution dikhao

      Answerx216−y212=1

      2b2a=6 se b2=3a milta hai, aur c2=28.

      a2+3a−28=0

      Isliye (a+7)(a−4)=0, a=4 aur b2=12.

    2. Foci (0,±5) aur latus rectum 323

      Solution dikhao

      Answery29−x216=1

      2b2a=323 se b2=16a3 milta hai, aur c2=25.

      3a2+16a−75=0

      Isliye (a−3)(3a+25)=0, a=3 aur b2=16, aur transverse axis y-axis ke saath hai.

  6. Short answerMediumNCERT Exercise 10.4 Q14

    Vertices (±2,0) aur eccentricity 32 wala hyperbola nikaalo.

    Solution dikhao

    Answerx24−y25=1

    a=2, isliye c=ae=3.

    b2=9−4=5
  7. Long answerHardNCERT Exercise 10.4 Q15

    Standard form wale ek hyperbola ke foci (±5,0) hain aur yeh (6,2) se guzarta hai. Uski equation nikaalo.

    Solution dikhao

    Answerx220−y25=1

    A=a2 lene par point se 36A−425−A=1 milta hai. Fractions hatao:

    A2−65A+900=0

    Isliye A=20 ya A=45. Lekin a<c=5 ke liye A<25 chahiye, isliye a2=20 aur b2=5.

  8. Quick answerMedium

    Har equilateral hyperbola (a=b) ki eccentricity hai

    Answer dekho

    Answer (B) 2

    c2=a2+a2=2a2, isliye e=ca=2. Value 12 us ellipse ki hai jismein b=c ho.
  9. Quick answerMedium

    Ek hyperbola ki eccentricity 2 hai aur uske foci 16 units ki doori par hain. Uske transverse axis ki length nikaalo.

    Answer dekho

    Answer 8

    2c=16 se c=8 milta hai; a=ce=4, isliye transverse axis 2a=8 hai.

Miscellaneous Examples

In har model mein pehla kaam axes ko aise chunna hai ki curve ki standard equation ho; uske baad questions sirf arithmetic reh jaate hain. Shuru karne se pehle neeche wali lab mein chaaron conics try karo.

InteractiveConic lab

Buttons se circle, parabola, ellipse ya hyperbola chuna jaata hai, aur ek aur button axis ko horizontal aur vertical ke beech badalta hai. Sliders size a (ya radius) aur eccentricity e set karte hain. Graph curve ko uske foci, parabola ke liye uski directrix, vertices aur ek latus rectum ke saath dikhata hai. Ek teesra slider, ya Play button, ek point P ko curve par chalata hai, aur P se foci tak (ya focus aur directrix tak) segments bante hain. Ek panel equation, a, b, c, e, latus rectum aur live distances dikhata hai, jo defining rule confirm karte hain: barabar distances, constant sum ya constant difference.

Fig. 10.16Ek conic chuno, a aur e badlo, aur P ko move karke uska distance rule check karo.
Example 10.17NCERT Example 17 · p. 202

Dish antenna

DTH dish ka receiver focus par hai, dish ke vertex se 36 cm door. Dish 16 cm gehri hai. Rim ke aar-paar yeh kitni chaudi hai?

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Example 10.18NCERT Example 18 · p. 202

Fountain ki dhaar

Paani ki ek dhaar ground level par ek nozzle se nikalti hai, sabse zyada 2 m ki height tak jaati hai, aur nozzle se 3 m door girti hai, aur ek parabola banati hai. Nozzle se kin horizontal distances par paani zameen se 1.5 m upar hai?

Pehle khud try karo. Phir solution ek-ek step karke kholo.

4/4P ki positions x29+y24=1 par hain.

Fig. 10.17Jaise-jaise ladder fisalti hai, mark kiya point ek ellipse ka hissa banata hai.NCERT Fig. 10.33 · p. 203

Ek vertical wall aur horizontal floor O par milte hain. 5 m ki ladder AB tiki hai, uska foot A floor par aur top B wall par hai, aur us par ek point P, A se 2 m aur B se 3 m door hai. Steps 1 se 3 ladder ko steep, 45 degrees par aur lagbhag flat dikhate hain, har baar P mark hai aur P ki pichhli positions halke dots ki tarah bachi hain. Step 4 P ki positions ko jod kar ellipse ka ek quarter banata hai aur uski equation deta hai, x squared over 9 plus y squared over 4 equals 1.

Example 10.19NCERT Example 19 · p. 203

Fisalti ladder

5 m ki ek ladder fisalti hai, uska foot A floor (x-axis) par aur top B wall (y-axis) se tika hai. Ladder par paint ka ek mark P, A se 2 m door hai. Dikhao ki P ek ellipse par chalta hai (Fig. 10.17).

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Quick check
3 mein se 1
Har equation ko uske curve se match karo.

Left mein koi item tap karo, phir right mein uska match.

Answer dekho
Answer
  • x2+y2=9 : circle
  • y2=9x : parabola
  • x29+y24=1 : ellipse
  • x29−y24=1 : hyperbola
Plus sign ke saath barabar squared terms circle dete hain; sirf ek squared variable parabola deta hai; plus ke saath alag denominators ellipse dete hain; squares ke beech minus sign hyperbola deta hai.
Timeline

History mein conics

  1. c. 350 BCE

    Menaechmus

    Conic sections ki pehli jaani-maani study, cube ko double karne ki problem par kaam karte hue.

  2. c. 200 BCE

    Apollonius

    Conics likhte hain aur ellipse, parabola aur hyperbola ko naam dete hain.

  3. 1609

    Kepler

    Planets ellipses par chalte hain aur Sun ek focus par hota hai.

  4. 1637

    Descartes

    La Géométrie curves ko equations mein badal deti hai.

  5. 1638

    Galileo

    Dikhate hain ki phenki gayi cheez parabola follow karti hai.

  6. 1679

    Fermat

    Plane aur solid loci par unka introduction, jo dashakon pehle likha gaya tha, print hota hai.

  7. 1687

    Newton

    Dikhate hain ki inverse-square gravity se bane orbits conics hote hain.

Recap

Summary aur key points

  1. Ek plane double cone ko axis se apne angle β ke hisaab se circle, ellipse, parabola ya hyperbola mein kaatta hai; vertex se guzarne par yeh ek point, ek line ya do lines deta hai (Section 10.2).
  2. Circle centre (h,k) se distance r par points ka set hai: (x−h)2+(y−k)2=r2 (Section 10.3).
  3. x2+y2+2gx+2fy+c=0 ka centre (−g,−f) aur radius g2+f2−c hai; ise padhne ke liye squares complete karo ((10.2)).
  4. Parabola un points ka set hai jo ek focus aur ek directrix se barabar door hain (Section 10.4).
  5. y2=4ax ka focus (a,0) aur directrix x=−a hai; squared variable axis batata hai aur sign direction (Section 10.4.1).
  6. Latus rectum axis ke perpendicular focal chord hai; y2=4ax ke liye iski length 4a hai (Section 10.4.2).
  7. Ellipse un points ka set hai jinke do foci se distances milkar ek constant 2a banate hain, jo major axis ki length hai (Section 10.5).
  8. Ellipse ke liye a2=b2+c2, aur e=ca<1 batata hai ki woh kitna flat hai (Section 10.5.1, Section 10.5.2).
  9. a>b ke saath x2a2+y2b2=1 ke foci (±c,0) hain; bada denominator major axis batata hai (Section 10.5.3).
  10. Ellipse aur hyperbola dono ke liye latus rectum 2b2a hai ((10.8)).
  11. Hyperbola un points ka set hai jinke do foci se distances mein ek constant 2a ka fark hai, jo transverse axis ki length hai (Section 10.6).
  12. Hyperbola ke liye c2=a2+b2 aur e>1; x2a2−y2b2=1 mein positive term transverse axis batata hai (Section 10.6.2).
  13. Reflectors, arches, cables aur sliding rods ko aise axes chun kar model kiya jaata hai jo standard equation dein (Miscellaneous Examples).
Practice · 11 questions

Practice questions answers ke saath (NCERT “Chapter 10 ki miscellaneous exercises”)

  1. NumericalEasyNCERT Miscellaneous Exercise Q1

    Ek torch ka reflector 12 cm chauda aur 3 cm gehra parabolic bowl hai. Bulb (focus) kahan lagna chahiye?

    Solution dikhao

    AnswerAxis par, vertex se 3 cm door.

    36=4a⋅3⇒a=3

    Focus (3,0) hai: axis par, vertex se 3 cm door.

  2. NumericalMediumNCERT Miscellaneous Exercise Q2

    Ek gateway vertical axis wale parabola ke shape ka hai: yeh 9 m ooncha hai aur zameen par 12 m tak faila hai. 5 m ki height par yeh kitna chauda hai?

    Solution dikhao

    Answer8 m

    Vertex top par ho to x2=−4ay point (6,−9) se guzarta hai.

    36=36a⇒a=1

    Isliye x2=−4y. 5 m ki height top se 4 m neeche hai, isliye y=−4: x2=16, x=±4 aur chaudai 8 m hai.

  3. NumericalHardNCERT Miscellaneous Exercise Q3

    Ek footbridge ka 120 m lamba level deck hai, jo vertical rods se ek parabolic cable par latka hai. Dono ends ki rods 32 m lambi hain aur centre wali sirf 8 m. Centre se 30 m door kitni lambi rod chahiye?

    Solution dikhao

    Answer14 m

    Vertex sabse neeche wale point par ho to x2=4ay. Ek end par x=60 hai aur cable vertex se 32−8=24 m upar hai.

    3600=96a⇒a=37.5

    x=30 par: y=900150=6, isliye rod 8+6=14 m lambi hai.

  4. NumericalMediumNCERT Miscellaneous Exercise Q4

    Ek tunnel ka entrance aadha ellipse hai, road level par 10 m chauda aur beech mein 3 m ooncha. Ek side se 2 m andar kitni headroom hai?

    Solution dikhao

    Answer2.4 m

    x225+y29=1

    x=3 par: y2=9(1−925)=14425, isliye y=2.4 m.

  5. Long answerMediumNCERT Miscellaneous Exercise Q5

    10 cm ki ek stick ke ends do coordinate axes par fisalte hain. Stick par x-axis wale end se 4 cm door ek dot P paint kiya gaya hai. Dot jis curve par chalta hai uski equation nikaalo.

    Solution dikhao

    Answerx236+y216=1

    Agar rod x-axis se angle θ banati hai, to P, y-axis wale end se 6 cm door hai.

    x=6cos⁡θ,y=4sin⁡θ
    x236+y216=1
  6. Short answerMediumNCERT Miscellaneous Exercise Q6

    y2=−20x ke vertex ko uske latus rectum ke dono ends se jodo. Jo triangle banta hai uska area kya hai?

    Solution dikhao

    Answer50 square units

    a=5, isliye ends (−5,10) aur (−5,−10) hain: base 20, height 5.

    12×20×5=50
  7. Short answerMediumNCERT Miscellaneous Exercise Q7

    Ek robotic lawn-mower do beacons se apne distances ka sum 26 m rakhta hai. Beacons 24 m ki doori par hain. Beacons ko x-axis par aur origin ko unke theek beech mein rakh kar iska raasta nikaalo.

    Solution dikhao

    Answerx2169+y225=1

    a=13 aur c=12.

    b2=169−144=25
  8. Long answerHardNCERT Miscellaneous Exercise Q8

    Ek triangle ka ek vertex y2=12x ke vertex par hai aur baaki do parabola par hain, axis ke around symmetric rakhe hue, taaki origin par angle right angle ho. Uski sabse lambi side ki length aur uska area nikaalo.

    Solution dikhao

    AnswerHypotenuse 24 aur area 144 square units

    Origin par right angle, jise axis barabar baantta hai, ka matlab hai ki har arm axis se 45∘ banati hai, isliye points (t,±t) hain.

    t2=12t⇒t=12

    Vertices (12,12) aur (12,−12) hain: hypotenuse 24 hai, aur area 12×24×12=144 hai.

  9. Quick answerHard

    k ki kin values ke liye x29−k+y25−k=1 ek hyperbola represent karta hai?

    Answer dekho

    Answer (B) 5<k<9

    Hyperbola ke liye dono denominators ke sign ulte hone chahiye: 9−k>0 aur 5−k<0, isliye 5<k<9. k<5 ke liye dono positive hain (ellipse); k>9 ke liye dono negative hain (koi real point nahi).
  10. Quick answerMedium

    Assertion (A): y2=4ax ke latus rectum ki length 4a hai. Reason (R): Latus rectum ka har end directrix se 2a door hai.

    Answer dekho

    Answer (A) A aur R dono true hain, aur R, A ko explain karta hai

    Har end directrix se 2a door hai, isliye definition se woh focus se bhi 2a door hai; dono halves milkar 4a banate hain. R hi reason hai.
  11. Quick answerHard

    Ek ellipse ka latus rectum uski minor axis ka aadha lamba hai. Uski eccentricity decimal mein nikaalo.

    Answer dekho

    Answer 0.866

    2b2a=b se b=a2 milta hai, isliye e2=1−b2a2=34 aur e=32≈0.866.

Apna NCERT exercise question dhoondo

Hamare practice questions ncert.ai ke liye likhe gaye hain aur NCERT exercises ko follow karte hain. Apni textbook ke question se match karne wala question dhoondo; uska answer uske saath hai.

Tumhari NCERT textbook meinYahan practice question
NCERT Exercise 10.1 Q1–Q4Practice 10.1 · Q1
NCERT Exercise 10.1 Q5Practice 10.1 · Q2
NCERT Exercise 10.1 Q6–Q9Practice 10.1 · Q3
NCERT Exercise 10.1 Q10–Q11Practice 10.1 · Q4
NCERT Exercise 10.1 Q12Practice 10.1 · Q5
NCERT Exercise 10.1 Q13Practice 10.1 · Q6
NCERT Exercise 10.1 Q14Practice 10.1 · Q7
NCERT Exercise 10.1 Q15Practice 10.1 · Q8
NCERT Exercise 10.2 Q1–Q6Practice 10.2 · Q1
NCERT Exercise 10.2 Q7–Q8Practice 10.2 · Q2
NCERT Exercise 10.2 Q9–Q10Practice 10.2 · Q3
NCERT Exercise 10.2 Q11–Q12Practice 10.2 · Q4
NCERT Exercise 10.3 Q1–Q6Practice 10.3 · Q1
NCERT Exercise 10.3 Q7–Q9Practice 10.3 · Q2
NCERT Exercise 10.3 Q10–Q12Practice 10.3 · Q3
NCERT Exercise 10.3 Q13–Q14Practice 10.3 · Q4
NCERT Exercise 10.3 Q15–Q16Practice 10.3 · Q5
NCERT Exercise 10.3 Q17–Q18Practice 10.3 · Q6
NCERT Exercise 10.3 Q19–Q20Practice 10.3 · Q7
NCERT Exercise 10.4 Q1–Q2Practice 10.4 · Q1
NCERT Exercise 10.4 Q3–Q6Practice 10.4 · Q2
NCERT Exercise 10.4 Q7–Q9Practice 10.4 · Q3
NCERT Exercise 10.4 Q10–Q11Practice 10.4 · Q4
NCERT Exercise 10.4 Q12–Q13Practice 10.4 · Q5
NCERT Exercise 10.4 Q14Practice 10.4 · Q6
NCERT Exercise 10.4 Q15Practice 10.4 · Q7
NCERT Miscellaneous Exercise Q1Chapter 10 ki miscellaneous exercises · Q1
NCERT Miscellaneous Exercise Q2Chapter 10 ki miscellaneous exercises · Q2
NCERT Miscellaneous Exercise Q3Chapter 10 ki miscellaneous exercises · Q3
NCERT Miscellaneous Exercise Q4Chapter 10 ki miscellaneous exercises · Q4
NCERT Miscellaneous Exercise Q5Chapter 10 ki miscellaneous exercises · Q5
NCERT Miscellaneous Exercise Q6Chapter 10 ki miscellaneous exercises · Q6
NCERT Miscellaneous Exercise Q7Chapter 10 ki miscellaneous exercises · Q7
NCERT Miscellaneous Exercise Q8Chapter 10 ki miscellaneous exercises · Q8

Quick check: MCQs

  1. 10.1 Introduction2 questions
  2. 10.2.2 Degenerated conic sections3 questions
  3. 10.3 Circle3 questions
  4. 10.4.2 Latus rectum4 questions
  5. 10.5.4 Latus rectum4 questions
  6. 10.6.3 Latus rectum4 questions
  7. Miscellaneous Examples3 questions
Glossary · 15

Key terms (English + Hindi)

circleवृत्तvritt
Plane ke un points ka set jo ek fixed point (centre) se ek fixed distance (radius) par hain.Chapter mein pehli baar yahan aaya →
conic sectionशंकु परिच्छेदshanku parichchhed
Woh curve jahan ek plane double cone ko kaatta hai: circle, ellipse, parabola ya hyperbola.Chapter mein pehli baar yahan aaya →
degenerate conic
Ek point, ek line ya lines ka pair, jo cone ke vertex se guzarne wale plane ke kaatne se milta hai.Chapter mein pehli baar yahan aaya →
directrixनियताniyata
Parabola ki definition wali fixed line.Chapter mein pehli baar yahan aaya →
eccentricityउत्केंद्रताutkendrata
Ratio e=c/a; ellipse ke liye 1 se kam, hyperbola ke liye 1 se zyada.Chapter mein pehli baar yahan aaya →
ellipseदीर्घवृत्तdeerghvritt
Plane ke un points ka set jinke do foci se distances milkar ek constant banate hain.Chapter mein pehli baar yahan aaya →
focusनाभिnaabhi
Conic ko define karne wala ek fixed point: parabola ka ek focus hota hai, ellipse aur hyperbola ke do.Chapter mein pehli baar yahan aaya →
generator
Cone ki surface par uske vertex se guzarti ek straight line; ise axis ke around ghumane se cone banta hai.Chapter mein pehli baar yahan aaya →
hyperbolaअतिपरवलयatiparvalay
Plane ke un points ka set jinke do foci se distances mein ek constant ka fark hai.Chapter mein pehli baar yahan aaya →
latus rectumनाभिलंबnaabhilamb
Focus se guzarti woh chord jo conic ke axis ke perpendicular ho.Chapter mein pehli baar yahan aaya →
major axisदीर्घ अक्षdeergh aksh
Ellipse ki sabse lambi chord, jo dono foci se guzarti hai; minor axis centre se guzarti woh chord hai jo iske perpendicular hai.Chapter mein pehli baar yahan aaya →
nappe
Double cone ke do halves mein se koi bhi ek, jo vertex par milte hain.Chapter mein pehli baar yahan aaya →
parabolaपरवलयparvalay
Plane ke un points ka set jo ek fixed point (focus) aur ek fixed line (directrix) se barabar door hain.Chapter mein pehli baar yahan aaya →
transverse axisअनुप्रस्थ अक्षanuprasth aksh
Hyperbola ka foci se guzarta axis; conjugate axis centre se guzarta hai aur iske perpendicular hai.Chapter mein pehli baar yahan aaya →
vertexशीर्षsheersh
Woh point jahan conic focus ya foci se guzarte apne axis se milta hai.Chapter mein pehli baar yahan aaya →