Inverse Trigonometric Functions: Class 12 Maths Chapter 2 Hinglish mein
Mathematics Part 1 · Hinglish notes, simulations aur practice · Official NCERT chapter PDF ↗
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Is chapter mein aap kya seekhenge
- Samjhao ki har trigonometric function ko inverse milne se pehle restrict kyun karna padta hai, aur uski principal value branch ke liye use hone wala interval batao.
- Chhahon inverse trigonometric functions ka domain aur principal range batao, aur ek branch ko line y = x mein reflect karke uska graph sketch karo.
- Standard arguments par, negative arguments bhi, inverse trigonometric functions ki principal values nikaalo.
- sin(sin⁻¹x) = x aur sin⁻¹(sin x) = x, aur unke jaise doosre results ko sirf unhi intervals par use karo jahan woh sahi hote hain, aur kisi bhi angle a ke liye sin⁻¹(sin a) jaise expressions evaluate karo.
- Sahi substitution se inverse trigonometric expressions simplify karo, aur naye angle ka interval dhyaan mein rakho.
- Right triangles aur addition formulae se inverse trigonometric functions ke sums aur compositions evaluate aur prove karo, aur unwale simple equations solve karo.
NCERT Mathematics Class 12, Chapter 2, pp. 18–33 par based original companion text. Yeh NCERT se juda nahi hai aur NCERT ne ise endorse nahi kiya hai.
2.1 Introduction
Phone ko tilt karo to uski screen tilt ko degrees mein dikha sakti hai. Andar laga accelerometer woh angle nahi naapta. Woh yeh naapta hai ki gravity ka kitna fraction phone ke lambe edge ke along lagta hai, aur woh fraction tilt ka sine hai. Degrees dikhane ke liye software ko sine ulta chalana padta hai: se use wapas nikaalna hota hai.
Kisi function ko ulta chalana uske inverse ka kaam hai, aur Chapter 1 ne humein bataya tha ki yeh kaam kab ho sakta hai: function one-one aur onto hona chahiye. Sine pehle test mein buri tarah fail hota hai: , , aur infinitely many doosre angles ke liye hai (Fig. 2.1). Yeh ek many-one function hai, aur baaki paanch trigonometric functions bhi aise hi hain.
4/4 par bilkul ek hi answer hai, .
Step 1 mein y = sin x ka graph lagbhag minus 2 pi se 2 pi tak dikhta hai, minus 1 aur 1 ke beech ek wave. Step 2 mein height one half par ek dashed horizontal line aati hai. Step 3 un chaar jagahon ko mark karta hai jahan line wave se milti hai, saath mein likha hai kai angles. Step 4 mein wave fade ho jaati hai, bas minus pi by 2 se pi by 2 tak ka piece bachta hai; woh strip shade hoti hai aur x = pi by 6 par sirf ek crossing rehti hai, jis par likha hai ek angle.
Ilaaj yeh hai ki domain ka kuch hissa chhod do. Agar hum tay kar lein ki sirf se tak ke angles dekhenge, to unmein se bilkul ek ka sine hai, aur ulte sawaal ka ek hi answer milta hai. Yeh chapter chhahon trigonometric functions ke liye aisa choice karta hai, usse bane inverse functions ke graphs banata hai aur unke rules nikaalta hai.
Yeh inverses sirf kisi technical problem ka jugaad nahi hain. Calculus mein yeh jaise integrals ke answers ke roop mein aate hain, aur surveyors, physicists aur engineers inhe tab use karte hain jab naapi gayi lengths se koi angle wapas nikaalna ho: road ka gradient, dish antenna ki elevation, robot arm ke joint angles.
Answer dekho
Answer (C) Alag-alag angles same sine dete hain, isliye yeh one-one nahi hai
Answer dekho
Answer Galat
2.2 Basic Concepts
Is section mein saara kaam pichhli classes ke do facts karte hain: har trigonometric function kahan rehta hai, aur kisi function ko invert karne ke liye kya chahiye. Pehla fact Table 2.1 mein ikattha kiya gaya hai.
| Function | Domain | Range |
|---|---|---|
Chhahon functions period ya ke saath khud ko repeat karte hain, isliye koi bhi apne natural domain par one-one nahi hai. Ab doosra fact.
Woh function jo kisi one-one aur onto function ka kaam ulta kar deta hai: yeh har output ko wapas input par bhejta hai. Inputs aur outputs apni jagah badal lete hain, isliye ka domain ki range hai, aur range domain.
Example par ka inverse hai.
Yeh ke har aur ke har ke liye sahi hain. Undo karna dono directions mein kaam karta hai, isliye bhi ka inverse hai. Isse har trigonometric function ka plan tay ho jaata hai: aisa interval chuno jis par woh one-one ho aur phir bhi apni range ki har value le, phir us piece ko invert karo.
Inverse sine
par sine function se tak lagaataar badhta hai aur beech ki har value se bilkul ek baar guzarta hai. Is interval par restrict karne se one-one aur onto hai, isliye iska inverse hai. Aise chhote kiye gaye interval ko restricted domain kehte hain.
Sirf yahi interval kaam nahi karta. par sine se tak lagaataar girta hai aur par phir badhta hai; asal mein integer ho to koi bhi interval chalega. jaisa interval kaam nahi karta, kyunki uspar curve upar jaakar wapas neeche aa jaata hai (Fig. 2.2).
2/4 par sine se tak badhta hai: one-one aur par onto.
Step 1 mein minus 2 pi se 2 pi tak sine curve dikhta hai. Step 2 minus pi by 2 se pi by 2 tak ki strip shade karta hai aur us piece ko mota aur blue banata hai, jo minus 1 se 1 tak badhta hai, us par likha hai principal piece. Step 3 iske badle pi by 2 se 3 pi by 2 tak ka piece orange mein highlight karta hai, jo 1 se minus 1 tak girta hai, us par likha hai yeh bhi one-one. Step 4 0 se pi tak ka piece dotted red line se highlight karta hai, saath mein height one half par ek horizontal line hai jo use do baar milti hai, us par likha hai do inputs: fail.
Har chalne wala interval ek alag inverse deta hai, jise ki ek branch kehte hain (padho “sine inverse” ya “arc sine”). Har branch ka domain hai; branches ki range alag hoti hai. Agreement se hum woh branch use karte hain jiski range hai. Yeh ki principal value branch hai.
Jin intervals par koi trigonometric function one-one aur onto hai, unmein se woh interval jo convention se uske inverse ki range ke roop mein fix kiya gaya hai. ke liye yeh hai.
ExampleRange wali ki branch ek valid branch hai, lekin principal nahi.
Shabdon mein, ka matlab hai ki aur . Yeh hamara pehla inverse trigonometric function hai, aur par lagi condition iski definition ka hissa hai. Jaise , phir bhi hai, nahi, kyunki sirf principal branch mein aata hai. Isse turant do facts milte hain. Pehla, har ke liye . Doosra, har ke liye , aur sirf wahin.
Graph banana. Maan lo invertible hai aur . Tab , isliye jab bhi ke graph par ho, point ke graph par hota hai. Har point ke coordinates swap karna plane ko line mein reflect karne jaisa hi hai. Isliye ka graph, ke principal piece ki us line mein mirror image hai (Fig. 2.3).
3/3Har point isi tarah reflect hota hai. Image hai, se tak.
Dono axes par equal scales, lagbhag minus 2 se 2 tak. Step 1 mein y = sin x ka blue piece minus pi by 2 se pi by 2 tak dikhta hai, end point P (pi by 2, 1) par. Step 2 dashed mirror line y = x aur image point P prime (1, pi by 2) par jodta hai, jo P se mirror ke across ek dotted segment se juda hai. Step 3 poori mirror image ko dashed red curve ke roop mein jodta hai, y = sin inverse x, jo (minus 1, minus pi by 2) se (1, pi by 2) tak jaata hai aur dono ends par steep hai.
Naye graph ko kisi bhi aur graph ki tarah padho. Yeh sirf ke liye exist karta hai, se tak badhta hai, aur apne ends par sabse steep hai, theek wahin jahan sine curve sabse flat tha. ki koi doosri branch kisi doosre piece ki mirror image hoti, jo -axis par upar ya neeche hoti.
Inverse cosine
Cosine ek even function hai, isliye yeh ke around symmetric kisi bhi interval par one-one nahi ho sakta. Iske badle hum use karte hain, jis par cosine se tak lagaataar girta hai. Doosre chalne wale intervals , aur, general roop mein, hain; har ek ki ek branch deta hai jiska domain hai.
To ka matlab hai ki aur . Piece ko mein reflect karne se ek curve milta hai jo se tak girta hai (Fig. 2.4). Dhyaan do ki negative number ka ek obtuse angle hota hai, kabhi negative nahi: poori range non-negative hai.
3/3 se upar curve tak jao aur phir side mein: .
Dono axes par equal scales. Step 1 mein poora cosine curve ek halki dotted line ke roop mein dikhta hai, aur x = 0 se x = pi tak ka piece mota aur blue hai, jo 1 se minus 1 tak girta hai. Step 2 dashed mirror line y = x aur red dashed image y = cos inverse x jodta hai, jo (minus 1, pi) se (1, 0) tak girti hai. Step 3 image par x = minus one half ke upar wala point mark karta hai, dono axes tak dotted guides ke saath; yeh height 2 pi by 3 par hai.
Answer dekho
Answer (C)
Answer dekho
Answer (B)
Answer dekho
Answer Galat
Inverse cosecant aur secant
Cosecant sine ka reciprocal hai, isliye jo sine piece humare paas pehle se hai wahi zyada kaam kar deta hai. par sine ek baar se guzarta hai. Reciprocal lene se har non-zero value ban jaati hai , ek aisa number jiska , lekin humein hatana padega, jahan sine zero hai. Jo bachta hai, , woh one-one tarike se un saare numbers par jaata hai jinka , yaani set , jo cosecant ki poori range hai.
Secant bhi isi tarah cosine piece se banta hai. par cosine ek baar se guzarta hai aur par zero hai; us point ko hata kar reciprocal lene se ka par ek one-one map milta hai.
Har hataya gaya point inverse graph ka ek asymptote ban jaata hai. Jaise-jaise badhta hai, dheere-dheere ki taraf aur ki taraf jaata hai, lekin dono kabhi wahan pahunchte nahi (Fig. 2.5). Doosri branches cosecant ke liye aur secant ke liye jaise sets se aati hain.
4/4 par se aur par se shuru hota hai; dono arms ke paas jaate hain.
Dono axes par lagbhag minus 3.5 se 3.5 tak equal scales. Step 1 mein y = cosec x ke do blue arms minus pi by 2 aur pi by 2 ke beech dikhte hain, ek y = 1 ke upar aur ek y = minus 1 ke neeche, jo y-axis ke paas tezi se badhte hain. Step 2 mirror line y = x aur red dashed image y = cosec inverse x jodta hai: x kam se kam 1 aur x zyada se zyada minus 1 ke liye do arms, jo heights pi by 2 aur minus pi by 2 se shuru hokar x-axis ki taraf flat hote jaate hain. Step 3 inki jagah 0 se pi par y = sec x ke do arms dikhata hai, x = pi by 2 par dashed vertical asymptote ke saath. Step 4 image y = sec inverse x jodta hai: ek arm x = 1 par 0 se badhta hai aur ek x = minus 1 par pi se girta hai, dono dashed line y = pi by 2 ke paas jaate hain.
In dono ke liye naye tables ki zaroorat kam hi padti hai. ke liye, jis angle ka secant hai, uska cosine hai, aur principal ranges bhi match karti hain, isliye . Isi tarah .
Inverse tangent aur cotangent
Do paas-paas ke asymptotes ke beech tangent har real number se bilkul ek baar guzarta hai. Origin ke sabse paas wala pair, , principal piece deta hai, jis par tangent one-one aur par onto hai. Isliye har real number accept karta hai, aur uski values strictly aur ke beech rehti hain.
Cotangent ke asymptotes ke multiples par hain, aur aur ke beech yeh har real number se ek baar girte hue guzarta hai. Woh interval, , iska principal piece hai.
Dono ranges open intervals hain. Kisi bhi real ke liye nahi hota, kyunki exist nahi karta. Restricted tangent aur cotangent ke vertical asymptotes unke inverses ke horizontal asymptotes ban jaate hain (Fig. 2.6). ki doosri branches , waghairah use karti hain; ki doosri branches , waghairah use karti hain.
2/4 saare ke liye defined hai aur lines ke beech rehta hai.
Lagbhag minus 3.5 se 3.5 tak equal scales. Step 1 mein blue curve y = tan x, x = minus pi by 2 aur pi by 2 par dashed vertical asymptotes ke beech dikhta hai. Step 2 mirror line y = x aur red dashed image y = tan inverse x jodta hai, jo poori picture ke across jaati hai aur y = pi by 2 aur y = minus pi by 2 par dashed horizontal lines ki taraf flat hoti jaati hai. Step 3 iske badle 0 se pi par y = cot x dikhata hai, jo x = 0 aur x = pi par asymptotes ke beech girta hai. Step 4 y = cot inverse x jodta hai, jo left mein pi ke paas se right mein 0 ke paas tak girta hai aur y-axis ko pi by 2 par kaatta hai.
Chhahon principal branches
Table 2.2 chhahon choices ko saath-saath rakhta hai. Ranges ko do families ki tarah yaad karo: , aur ke aas-paas, ke andar angles dete hain; , aur ke andar angles dete hain.
| Function | Domain | Principal range |
|---|---|---|
Lab se table ko test karo. Principal branch par readout hamesha upar di gayi range mein aata hai. Paas wali branch par switch karo to same input ek alag angle deta hai jiska sine, cosine ya tangent same hai. Secant ke liye input try karo: lab mana kar deta hai, kyunki kisi angle ka secant nahi hota.
Unit circle se dono families ko imagine karna aasaan ho jaata hai (Fig. 2.8). aur ki principal values woh angles hain jo circle ke right half par khatam hote hain; aur ki values upper half par khatam hoti hain. Principal value nikaalne ke liye diye gaye ratio wale angles dhoondho aur sahi half wala rakho.
3/4Line circle se aur par milti hai; upar wala hai.
Left mein ek unit circle aur right mein notes panel. Step 1 circle ke right half ko blue mein mota karta hai, neeche minus pi by 2 se upar pi by 2 tak, aur panel sin inverse aur tan inverse ki ranges list karta hai. Step 2 upper half ko orange mein mota karta hai, right mein 0 se left mein pi tak, aur panel cos inverse aur cot inverse list karta hai. Step 3 vertical line x = minus one half banata hai, jo circle se upar 2 pi by 3 par aur neeche minus 2 pi by 3 par milti hai; upar wala point bhara hua hai aur centre se juda hai, isliye cos inverse of minus one half 2 pi by 3 hai. Step 4 horizontal line y = minus one half banata hai, jo circle se right mein minus pi by 6 par aur left mein 7 pi by 6 par milti hai; right wala point rakha jaata hai, isliye sin inverse of minus one half minus pi by 6 hai.
Woh ek answer jo inverse trigonometric function apni principal branch fix hone ke baad deta hai: diye gaye ratio wala woh angle jo us branch mein aata hai.
Example, lekin ki principal value hai.
Inverse sine ki principal value
ki principal value nikaalo.
Pehle khud try karo. Phir solution ek-ek step karke kholo.
Inverse cotangent ke liye negative input
ki principal value nikaalo.
Pehle khud try karo. Phir solution ek-ek step karke kholo.
Secant aur cosecant ke liye negative inputs
(a) aur (b) ki principal values nikaalo.
Pehle khud try karo. Phir solution ek-ek step karke kholo.
Answer dekho
Answer -0.25 π
Answer dekho
Answer (D)
Answer dekho
- (A)
- (C)
Left mein koi item tap karo, phir right mein uska match.
Answer dekho
- :
- :
- :
- :
Neeche ke practice set ke Questions 1 se 12 mein answer ko ke roop mein type karo: ke liye -1/3 type karo, aur ke liye 1.
Practice 2.1: answers ke saath
ki principal value nikaalo.
πSolution dikhao
, aur mein aata hai. Principal value hai.
ki principal value nikaalo.
πSolution dikhao
aur , isliye principal value hai.
ki principal value nikaalo.
πSolution dikhao
ka matlab hai . ke saath .
ki principal value nikaalo.
πSolution dikhao
aur , isliye principal value hai.
ki principal value nikaalo.
πSolution dikhao
, isliye . Angle mein aata hai, isliye yahi principal value hai.
ki principal value nikaalo.
πSolution dikhao
. Isliye , aur mein aata hai. Principal value hai.
ki principal value nikaalo.
πSolution dikhao
aur mein aata hai, isliye . se compare karo: ko ki range chhodti hai, ki nahi.
ki principal value nikaalo.
πSolution dikhao
aur , isliye principal value hai.
ki principal value nikaalo.
πSolution dikhao
aur ka right-hand end hai, isliye .
ki principal value nikaalo.
πSolution dikhao
ka matlab hai , aur mein isse milta hai.
ki value nikaalo.
πSolution dikhao
, aur . Total hai.
ki value nikaalo.
πSolution dikhao
aur , isliye value hai.
ke baare mein kaun sa statement har real ke liye sahi hai?
Answer dekho
Answer (C)
ki principal branch open interval hai: aur exist nahi karte, isliye bade ke liye ke paas aata hai lekin kabhi uske barabar nahi hota. ki range hai, aur .kiske barabar hai?
Answer dekho
Answer (B)
aur , isliye value hai. lene par, jo uski range ke bahar hai, aata hai.
2.3 Inverse Trigonometric Functions ki Properties
Is section ki har identity ke saath fine print hai. Woh sirf un ke liye sahi hai jahan dono sides defined hon aur jo angles aate hain woh principal branches ke andar rahein. Fine print ko ignore karna is chapter mein galat answers ki sabse common wajah hai, isliye neeche har result ke saath uska interval diya gaya hai.
ke liye , aur ke liye . Isi tarah ke liye aur ke liye ; har real ke liye aur ke liye . Baaki teen functions apni-apni branches par isi pattern ko follow karte hain.
Dono halves ek jaise nahi hain. Pehla, , ke poore domain par sahi hai. Doosra tab toot jaata hai jaise hi se bahar jaata hai: jaise , nahi. ka graph dikhata hai ki iske badle kya hota hai (Fig. 2.9).
3/3 par graph deta hai.
Equal scales, x lagbhag minus pi se 2 pi tak. Step 1 minus pi by 2 se pi by 2 tak ki strip shade karta hai, jahan ek chhota blue segment bilkul dashed line y = x par hai. Step 2 baaki blue graph jodta hai: ek zigzag jiska slope pi by 2 se 3 pi by 2 par minus pi by 2 tak minus 1 hai, phir slope dobara 1, aur left mein bhi waisa hi mod, jo kabhi pi by 2 se upar ya minus pi by 2 se neeche nahi jaata. Step 3 x = 5 pi by 4 ke upar wala point mark karta hai, jo height minus pi by 4 par hai, dono axes tak dotted guides ke saath.
Zigzag ka slope par , par , par phir se hai, aur yeh period ke saath repeat hota hai. Kisi bhi ke liye evaluate karne ke liye, aur use karke ki jagah ka same sine wala angle rakho. Yahi idea baaki functions ke liye unki apni symmetries ke saath kaam karta hai, jaise aur .
Zyaadatar simplifications ek hi recipe follow karte hain. ko kisi naye angle ka trigonometric function maan lo, expression ko standard identity se dobara likho, aur upar wali property se inverse cancel karo. Dhyaan aakhri step mein chahiye: cancel karne se pehle check karo ki jis angle tak tum pahunche ho woh sahi principal branch mein hai.
Ek expression, do answers
Dikhao ki ke liye , aur ke liye .
Pehle khud try karo. Phir solution ek-ek step karke kholo.
Fig. 2.10 Example 3 ki dono sides ko compare karta hai. par woh ek ho jaati hain. par curve se upar chala jaata hai, jo height ki koi value reach nahi kar sakti, isliye left-hand side ko wapas mudna padta hai.
3/3 par dono match karte hain. par woh aur dete hain, aur .
x-axis minus 1 se 1 tak aur y-axis 0 se 2 pi tak hai. Step 1 blue curve y = 2 cos inverse x dikhata hai, jo x = minus 1 par 2 pi se x = 1 par 0 tak girta hai. Step 2 orange dashed curve y = cos inverse of (2 x squared minus 1) jodta hai, jo x = minus 1 par 0 se x = 0 par pi tak badhta hai aur wapas 0 tak girta hai, y-axis ke around symmetric. Step 3 0 se 1 tak ka hissa shade karta hai, jis par likha hai yahan equal, jahan dono curves ek ho jaate hain, aur x = minus one half mark karta hai, jahan blue curve 4 pi by 3 par aur orange wala 2 pi by 3 par hai.
Inverse tangent ke andar sum-to-product
, , ko simplest form mein likho.
Pehle khud try karo. Phir solution ek-ek step karke kholo.
Ek surd jismein angle chhupa hai
, , ko simplest form mein likho.
Pehle khud try karo. Phir solution ek-ek step karke kholo.
Answer dekho
Answer (D)
Answer dekho
Answer 0.3333333333333333 π
Answer dekho
Answer (A)
Answer dekho
Answer Sahi
Practice 2.2: answers ke saath
Prove karo ki ke liye .
Solution dikhao
Maan lo , jahan . Kyunki , , aur .
Yahan , jo ki branch ke bahar hai. Lekin aur .
Prove karo ki ke liye .
Solution dikhao
Maan lo . Kyunki , . Tab
Kyunki , . ( ke liye angle ko paar kar jaata hai, aur right side ban jaati hai.)
, , ko simplest form mein likho.
Solution dikhao
Answer
Maan lo , , isliye aur .
aur lene par aur , jahan kyunki .
Kyunki , expression ke barabar hai.
, , ko simplest form mein likho.
Solution dikhao
Answer
ke liye angle mein aata hai, isliye expression ke barabar hai.
, , ko simplest form mein likho.
Solution dikhao
Answer
Upar aur neeche dono ko aadha karne se aur milte hain.
Isliye fraction hai. ke liye angle mein aata hai, isliye expression ke barabar hai.
, , ko simplest form mein likho.
Solution dikhao
Answer
Maan lo , jahan . Tab (positive), aur
Kyunki mein hai, .
, , , ko simplest form mein likho.
Solution dikhao
Answer
Ab , isliye expression ke barabar hai.
ki value nikaalo. ke liye type karo.
πSolution dikhao
, isliye andar wala angle hai aur . Phir .
Real aur ke liye ko aur mein nikaalo.
Solution dikhao
Answer
Maan lo aur , dono mein, jahan cosine positive hai. Isliye aur , aur isi tarah ke liye.
nikaalo. ke liye type karo.
πSolution dikhao
, aur branch mein aata hai. Isliye value hai, nahi.
nikaalo. ke liye type karo.
πSolution dikhao
, aur mein aata hai. Isliye value hai.
ki value nikaalo. 3/7 jaisa fraction chalega.
Solution dikhao
Agar , to jis triangle ki opposite side aur hypotenuse hai uski adjacent side hai, isliye . Agar to .
kiske barabar hai?
Answer dekho
Answer (D)
aur , isliye value hai. Answer ki range ko ignore karta hai.kiske barabar hai?
Answer dekho
Answer (B)
, isliye value hai. Iske badle lene par aata hai, yahi trap hai.kiske barabar hai?
Answer dekho
Answer (A)
aur , isliye sum hai. lene par aata hai. Asal mein har real ke liye .
Miscellaneous examples
Branch ke bahar ka angle
nikaalo.
Pehle khud try karo. Phir solution ek-ek step karke kholo.
ya jaise compositions right triangle se solve hote hain. Andar wale angle ko naam do, ek triangle banao jiski sides diye gaye ratio mein fit hon, Pythagoras se teesri side nikaalo aur jo ratio chahiye woh padh lo (Fig. 2.11). Negative input ke liye triangle answer ka size deta hai, aur ka quadrant uska sign.
3/3Ab aur , isliye .
Ek right triangle jiska angle theta left corner par aur right angle neeche right mein hai. Upar ek panel kehta hai theta equals sin inverse of 7 by 25. Step 1 theta ke saamne wali chhoti vertical side par 7 aur tirchhe hypotenuse par 25 likhta hai, aur base par question mark lagata hai. Step 2 base ko orange karta hai aur us par 24 likhta hai, aur panel dikhata hai square root of 25 squared minus 7 squared equals 24. Step 3 sides ko adjacent aur opposite naam deta hai, aur panel par likha hai cos theta equals 24 by 25 aur tan theta equals 7 by 24.
Quadrant par nazar rakho
(a) aur (b) nikaalo.
Pehle khud try karo. Phir solution ek-ek step karke kholo.
Answer dekho
Answer 0.25 π
Answer dekho
Answer (B)
Answer dekho
Answer Galat
Inverse trigonometric functions tak ke safar ke milestones
- 499 CE
Āryabhaṭīya
ke steps par half-chords (jyā) ka table.
- c. 629 CE
Bhāskara I
Sine ko approximate karne wala ek simple rational formula.
- 665 CE
Brahmagupta
Sine tables ke liye second-order interpolation.
- 1150 CE
Bhāskara II
aur jaisi exact values.
- c. 1400
Mādhava
Arc tangent, , aur ki series.
- c. 1530
Yuktibhāṣā
Kerala series ke proofs, Malayalam mein likhe gaye.
- 1813
John Herschel
Arc sine ke liye notation introduce karte hain.
Principal branches: jaldi se yaad karo
Summary aur key points
- Trigonometric function apne natural domain par many-one hota hai, isliye uska inverse tabhi hota hai jab uske domain ko aise interval par restrict kiya jaaye jahan woh one-one aur onto ho (Section 2.1).
- Agar one-one aur onto hai, to aur , aur ka graph line mein ke graph ki mirror image hai (Section 2.2).
- Har chalne wala interval inverse ki ek branch deta hai. Tay ki gayi branch principal value branch hai, aur usse li gayi value principal value hai (Inverse sine).
- aur (Inverse cosine).
- aur ke liye defined hain, ranges aur ke saath (Inverse cosecant aur secant).
- aur har real ke liye defined hain, open ranges aur ke saath (Inverse tangent aur cotangent).
- ek angle hai, jabki ek reciprocal hai. Jab koi branch naam se na batayi jaaye, to principal branch hi samjho (Chhahon principal branches).
- Negative input ke liye , aur negative angle dete hain, jabki , aur aur ke beech ka angle dete hain (negative inputs).
- par , lekin sirf par; baaki har function apni branch par yahi do rules follow karta hai (Property).
- Branch ke bahar wale ke liye nikaalne ke liye, ki jagah ka same sine wala angle rakho (Example 6).
- , ya jaise substitutions inverse trigonometric expressions ko simplify karte hain; ka interval final form tay karta hai (Example 3).
- jaise compositions right triangle se padhe jaate hain, aur sign principal value ke quadrant se tay hota hai (Fig. 2.11).
Practice questions answers ke saath (NCERT “Chapter 2 par miscellaneous exercises”)
ki value nikaalo. ke liye type karo.
πSolution dikhao
, isliye . Kyunki , value hai.
ki value nikaalo. ke liye type karo.
πSolution dikhao
, aur mein aata hai. Isliye value hai.
Prove karo ki .
Solution dikhao
Maan lo . Opposite side aur hypotenuse wale triangle ki adjacent side hai, isliye .
Kyunki , , isliye ki branch mein aata hai. Isliye .
Prove karo ki .
Solution dikhao
aur ke saath aur .
Dono angles acute hain aur , isliye . Isliye .
Prove karo ki .
Solution dikhao
Maan lo aur , dono acute, isliye aur .
Kyunki ki branch mein aata hai, .
Maan lo aur .
Prove karo ki .
Solution dikhao
aur , isliye
Kyunki , .
Dikhao ki , aur samjhao ki kyun nahi hai.
Solution dikhao
.
Lekin , isliye obtuse hai, jabki acute hai. Sahi statement hai.
Prove karo ki .
Solution dikhao
Agar , to aur . Saath hi , isliye .
Dono angles acute hain aur , isliye , aur aisa ek hi angle jiska tangent hai woh hai.
Prove karo ki ke liye .
Solution dikhao
Maan lo , jahan , isliye aur .
Saath hi , jahan , isliye . Dono sides barabar hain.
Prove karo ki ke liye .
Solution dikhao
Maan lo aur . Tab .
ke liye , isliye aur . Inka difference hai, isliye input hai.
Kyunki ki branch mein aata hai, expression ke barabar hai.
Prove karo ki ke liye .
Solution dikhao
Maan lo , jahan , isliye aur .
Kyunki , square root hai, aur .
solve karo.
Solution dikhao
Isliye ya . ke liye dono inverse tangents negative hain, aur sum hai, nahi, isliye yeh root reject hota hai. ke liye sum hai. Solution hai.
ke liye solve karo. ko 4 decimal places tak do.
Solution dikhao
Maan lo , jahan . Tab , jahan , isliye left side hai.
Equation ban jaata hai , isliye aur . Check: is ke liye .
, , kiske barabar hai?
Answer dekho
Answer (C)
ke saath opposite side hai, isliye ; yeh positive hai, jaisa ke liye hona chahiye. Option A cotangent hai.Agar , to kiske barabar hai?
Answer dekho
Answer (B)
Cosines lene par , isliye , jisse hona zaroori hai aur milta hai. Isliye ; check: . Value deti hai, jiska sign galat hai.ko ke multiple ke roop mein nikaalo. ke liye type karo.
πAnswer dekho
Answer 1 π
. Dono angles mein hain, isliye unka sum mein hai aur ke barabar hai. jodne par milta hai.True ya false: (angles radians mein).
Answer dekho
Answer Galat
, isliye property lagu nahi hoti. Kyunki aur branch mein aata hai, .In values ko sabse chhoti se sabse badi tak arrange karo.
Answer dekho
AnswerValues , , , aur hain.Har expression ko uski principal value se match karo.
Left mein koi item tap karo, phir right mein uska match.
Answer dekho
Answer- :
- :
- :
- :
Negative inputs ke liye aur negative angles dete hain; aur minus acute angle dete hain.Inmein se kaun se ke barabar hain?
Saare sahi options chunoAnswer dekho
Answer- (A)
- (C)
- (E)
, jabki .
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 mein | Yahan practice question |
|---|---|
| NCERT Exercise 2.1, Q1 | Practice 2.1 · Q1 |
| NCERT Exercise 2.1, Q2 | Practice 2.1 · Q2 |
| NCERT Exercise 2.1, Q3 | Practice 2.1 · Q3 |
| NCERT Exercise 2.1, Q4 | Practice 2.1 · Q4 |
| NCERT Exercise 2.1, Q5 | Practice 2.1 · Q5 |
| NCERT Exercise 2.1, Q6 | Practice 2.1 · Q6 |
| NCERT Exercise 2.1, Q7 | Practice 2.1 · Q7 |
| NCERT Exercise 2.1, Q8 | Practice 2.1 · Q8 |
| NCERT Exercise 2.1, Q9 | Practice 2.1 · Q9 |
| NCERT Exercise 2.1, Q10 | Practice 2.1 · Q10 |
| NCERT Exercise 2.1, Q11 | Practice 2.1 · Q11 |
| NCERT Exercise 2.1, Q12 | Practice 2.1 · Q12 |
| NCERT Exercise 2.1, Q13 | Practice 2.1 · Q13 |
| NCERT Exercise 2.1, Q14 | Practice 2.1 · Q14 |
| NCERT Exercise 2.2, Q1 | Practice 2.2 · Q1 |
| NCERT Exercise 2.2, Q2 | Practice 2.2 · Q2 |
| NCERT Exercise 2.2, Q3 | Practice 2.2 · Q3 |
| NCERT Exercise 2.2, Q4 | Practice 2.2 · Q4 |
| NCERT Exercise 2.2, Q5 | Practice 2.2 · Q5 |
| NCERT Exercise 2.2, Q6 | Practice 2.2 · Q6 |
| NCERT Exercise 2.2, Q7 | Practice 2.2 · Q7 |
| NCERT Exercise 2.2, Q8 | Practice 2.2 · Q8 |
| NCERT Exercise 2.2, Q9 | Practice 2.2 · Q9 |
| NCERT Exercise 2.2, Q10 | Practice 2.2 · Q10 |
| NCERT Exercise 2.2, Q11 | Practice 2.2 · Q11 |
| NCERT Exercise 2.2, Q12 | Practice 2.2 · Q12 |
| NCERT Exercise 2.2, Q13 | Practice 2.2 · Q13 |
| NCERT Exercise 2.2, Q14 | Practice 2.2 · Q14 |
| NCERT Exercise 2.2, Q15 | Practice 2.2 · Q15 |
| NCERT Miscellaneous Exercise, Q1 | Chapter 2 par miscellaneous exercises · Q1 |
| NCERT Miscellaneous Exercise, Q2 | Chapter 2 par miscellaneous exercises · Q2 |
| NCERT Miscellaneous Exercise, Q3 | Chapter 2 par miscellaneous exercises · Q3 |
| NCERT Miscellaneous Exercise, Q4 | Chapter 2 par miscellaneous exercises · Q4 |
| NCERT Miscellaneous Exercise, Q5 | Chapter 2 par miscellaneous exercises · Q5 |
| NCERT Miscellaneous Exercise, Q6 | Chapter 2 par miscellaneous exercises · Q6 |
| NCERT Miscellaneous Exercise, Q7 | Chapter 2 par miscellaneous exercises · Q7 |
| NCERT Miscellaneous Exercise, Q8 | Chapter 2 par miscellaneous exercises · Q8 |
| NCERT Miscellaneous Exercise, Q9 | Chapter 2 par miscellaneous exercises · Q9 |
| NCERT Miscellaneous Exercise, Q10 | Chapter 2 par miscellaneous exercises · Q10 |
| NCERT Miscellaneous Exercise, Q11 | Chapter 2 par miscellaneous exercises · Q11 |
| NCERT Miscellaneous Exercise, Q12 | Chapter 2 par miscellaneous exercises · Q12 |
| NCERT Miscellaneous Exercise, Q13 | Chapter 2 par miscellaneous exercises · Q13 |
| NCERT Miscellaneous Exercise, Q14 | Chapter 2 par miscellaneous exercises · Q14 |
Quick check: MCQs
- 2.1 Introduction2 questions
- Inverse cosine3 questions
- Chhahon principal branches4 questions
- 2.3 Inverse Trigonometric Functions ki Properties4 questions
- Miscellaneous examples3 questions
Key terms (English + Hindi)
- asymptoteअनंतस्पर्शीanantasparshi
- Aisi line jiske graph kareeb, aur kareeb aata jaata hai lekin use kabhi chhoota nahi, jaise ke liye .Chapter mein pehli baar yahan aaya →
- branchशाखाshaakhaa
- Ek interval jis par trigonometric function one-one aur apni range par onto ho, ya usse milne wala inverse.Chapter mein pehli baar yahan aaya →
- inverse functionप्रतिलोम फलनpratilom phalan
- Bijection ke liye woh function jo har ko wapas par bhejta hai.Chapter mein pehli baar yahan aaya →
- inverse trigonometric functionप्रतिलोम त्रिकोणमितीय फलनpratilom trikonmitiya phalan
- Ek branch par restrict kiye gaye trigonometric function ka inverse; jaise ka woh angle hai jiska sine hai.Chapter mein pehli baar yahan aaya →
- many-one functionबहुएक फलनbahu-ek phalan
- Aisa function jo do ya zyada alag inputs ko same output par bhejta hai, isliye woh one-one nahi hota.Chapter mein pehli baar yahan aaya →
- one-one aur onto functionएकैकी आच्छादक फलनone-one and onto functionekaiki aachchhaadak phalan
- Aisa function jo one-one aur onto dono ho; sirf aise functions ke hi inverses hote hain.Chapter mein pehli baar yahan aaya →
- principal valueमुख्य मानmukhya maan
- Woh angle jo inverse trigonometric function apni principal value branch se deta hai, jaise ke liye .Chapter mein pehli baar yahan aaya →
- principal value branchमुख्य मान शाखाmukhya maan shaakhaa
- Woh branch jo convention se kisi inverse trigonometric function ki range ke roop mein fix ki gayi hai, jaise ke liye .Chapter mein pehli baar yahan aaya →
- restricted domainप्रतिबंधित प्रांतpratibandhit praant
- Function ke natural domain ka ek hissa, jo is tarah chuna jaata hai ki function one-one aur apni range par onto ban jaaye.Chapter mein pehli baar yahan aaya →