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If /Aand /Bare acute angles such that c...

If `/_A`and `/_B`are acute angles such that `cos A=cos B`. then show that `/_A=/_B`.

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Construct `DeltaABC` , right - angled at A such that
`cosA=cosB`
`rArr(AC)/(AB)=(BC)/(AB)`
`rArrAC=BC`
`rArrangleB=angleA`
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If A and B are positive acute angles and cos A = 1/7, cos B = 13/14 , then show that A-B=60^0 .

In a triangle A B C ,/_A B C=/_A C B and the bisectors of /_A B C and /_A C B intersect at O such that /_B O C=120^0dot Show that /_A=/_B=/_C=60^0

In a triangle A B C ,\ /_A B C=\ /_A C B and the bisectors of /_A B C\ a n d\ /_A C B intersect at O such that /_B O C=120^0dot Show that /_A=/_B=/_C=60^0 .

If ray O C stands on line A B such that /_A O C=/_C O B , then show that /_A O C=90^0

In Fig.9, if ray O C stands on line A B such that /_A O C=/_C O B , then show that /_A O C=90^0dot

ABC and DBC are two isosceles triangles on the same base BC (see Fig. 7.33). Show that /_A B D\ =/_A C D

In a /_\A B C , right angled at C and /_A=/_B , is cosA=cosB ?

Find acute angles A and B, if sin(A+B)=cos(A-B)=sqrt(3)/2 .

In a right angled triangle, one acute angle is double the other. Prove that the hypotenuse is double the smallest side. GIVEN : A A B C in which /_B=90^0 and /_A C B=2/_C A B . to prove : A C=2B C

If one of the angles A,B,C of a triangle is not acute, show that cos^2A+cos^2B+cos^2C=1

NAGEEN PRAKASHAN ENGLISH-INTRODUCTION TO TRIGONOMETRY-Problems From NCERT/exemplar
  1. given : 15 cotA = 8 find sinA and secA

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  2. If s in A=3/4 , calculate cos A and tan A.

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  3. If /Aand /Bare acute angles such that cos A=cos B. then show that /A=...

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  4. Evaluate: (cos45)/(sec30+cosec30)

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  5. solve : (2tan30^@)/(1+tan^2 30^@)

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  6. If tan(A+B)=sqrt(3) and t a n(A B)=1/(sqrt(3)); 0o<A+Blt=90o;""...

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  7. In DeltaA B C , right-angled at B, A B"\ "="\ "5"\ "c m and /A C B=30...

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  8. In P Q R , right-angled at Q ,\ P Q=3c m and P R=6c m . Determine ...

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  9. Prove that : sqrt((1-cos^(2)theta)sec^(2)theta)=tantheta

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  10. Prove (tantheta+2)(2tantheta+1)=5tantheta+2sec^2theta.

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  11. If cosA+cos^(2)A=1, then prove that sin^(2)A+sin^(4)A=1.

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  12. Prove the following identity: sec^4theta-sec^2theta=tan^4theta+tan^2th...

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  13. Show that 1+cot^2alpha / (1+cosec alpha)=cosec alpha

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  14. (sinalpha + cosalpha)(tanalpha + cotalpha) = secalpha + cosecalpha

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  15. about to only mathematics

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  16. If 2sin^(2)theta-cos^(2)theta=2, then find the value of theta.

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  17. if tantheta+sectheta=l then prove that sectheta=(l^2+1)/(2l)

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  18. If asintheta+bcostheta=c then prove that acostheta-bsintheta=sqrt(a^2+...

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  19. If sintheta+costheta=pandsectheta+"cosec"theta=q then prove that q(p^(...

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  20. Prove that : tantheta+tan(90^(@)-theta)=sectheta*sec(90^(@)-theta)

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