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Prove that: cos^2pi/8+sin^2(3pi)/8+sin^2...

Prove that: `cos^2pi/8+sin^2(3pi)/8+sin^2(5pi)/8_sin^2(7pi)/8=2`

A

`-1`

B

1

C

`-2`

D

2

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The correct Answer is:
D
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cos^2(pi/8) +cos^2((3pi)/8) +cos^2((5pi)/8)+cos^2 ((7pi)/8)=2

Prove that: cos^4pi/8+cos^4(3pi)/8+cos^4(5pi)/8+cos^4(7pi)/8=3/2

Prove that: cos^4pi/8+cos^4(3pi)/8+cos^4(5pi)/8+cos^4(7pi)/8=3/2

Prove that: sin^2pi/(18)+sin^2pi/9+sin^2(7pi)/(18)+sin^2(4pi)/9=2

Prove that: sin^2pi/(18)+sin^2pi/9+sin^2(7pi)/(18)+sin^2(4pi)/9=2

Prove that: sin^4(pi/8)+sin^4((3pi)/8)+sin^4((5pi)/8)+sin^4((7pi)/8)=3/2

Prove that: cos^4(pi/8)+cos^4((3pi)/8)+cos^4((5pi)/8)+cos^4((7pi)/8)=3/2

cos^4(pi/8)+cos^4((3pi)/8)+cos^4((5pi)/8)+cos^4((7pi)/8)=

NAGEEN PRAKASHAN ENGLISH-TRIGNOMETRIC FUNCTIONS-EXERCISES 3P
  1. If 2costheta=x+1/x, then 2cos2theta=?

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  2. If A+B=45^(@) , show that (1+tanA)(1+tan B)=2.

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  3. Prove that: cos^2pi/8+sin^2(3pi)/8+sin^2(5pi)/8sin^2(7pi)/8=2

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  4. If sinx+sin^(2)x=1 ,then cos^(4)x+cos^(2)x=?

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  5. If 4sin^(2)theta=3, then general value of theta is:

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  6. If sin7theta=cos5 theta, then general value of theta is:

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  7. If tan3theta=cottheta, then general value of theta is :

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  8. Find the general value of theta from the equation tantheta+tan2theta+t...

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  9. Solve the following equation : cottheta+t a ntheta=2

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  10. The solution of cos2theta=cos^(2)theta is:

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  11. cottheta=-sqrt(3) and cosec theta=2

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  12. Solve: 2sin^(2)theta+sin^(2)2theta=2

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  13. If sqrt(3)sintheta-costheta=0, then one general value of theta is:

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  14. In DeltaABC, a=12 m, angleB=30^(@) and angleC=90^(@), then area of Del...

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  15. In DeltaABC, a=12 cm, angleB=30^(@) and angleC=90^(@), then area of De...

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  16. In DeltaABC, cotA/2, cotB/2, cotC/2 are in A.P., then the true stateme...

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  17. In DeltaABC, if a,b,c are in A.P. prove that: cot(A/2),cot(B/2), cot...

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  18. In DeltaABC, a=9, b=8 and c=4, then 3cosB-6cosC=?

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  19. In DeltaABC, If 1/(a+b)+1/(b+c)=3/(a+b+c), then angleB=?

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  20. In any DeltaABC, prove that a^(3)cos(B-C)+b^(3)cos(C-A)+c^(3)cos(A-B)...

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