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Prove that: cos^4pi/8+cos^4(3pi)/8+cos^4...

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

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

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

cos^2(pi/8) +cos^2((3pi)/8) +cos^2((5pi)/8)+cos^2 ((7pi)/8)=2

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

Prove that : cos(pi/7)cos((2pi)/7) cos((3pi)/7)=1/8

Prove that: cos(pi/7)cos((2pi)/7)cos((4pi)/7)=-1/8

Prove that: cos(pi/7)cos(2pi/7)cos(4pi/7)=-1/8,

Statement I : sin^2pi/8+sin^2(3pi)/8+sin^2(5pi)/8+sin^2(7pi)/8=2 Statement II sin^4pi/8+sin^4 (3pi)/8+sin^4(5pi)/8sin^4(7pi)/8=3/2

Prove that: cos(pi/5)cos((2pi)/5)cos((4pi)/5)cos((8pi)/5)=(-1)/16

Prove that "cos"(pi)/9."cos"(2pi)/9."cos"(3pi)/9."cos"(4pi)/9=1/(2^(4))

RD SHARMA ENGLISH-TRIGONOMETRIC RATIOS OF MULTIPLE AND SUBMULTIPLE ANGLES-All Questions
  1. Find general solution of the trigonometric equation sin5theta =1

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

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

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  4. Prove that:tan6^0tan42^0tan66^0tan78^0=1.

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  5. If tanalpha=(1-cosbeta)/(sinbeta),t h e n (a)tan3alpha=tan2beta (b) ...

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  6. Prove that: sin36^0=(sqrt(10-2sqrt(5)))/4 .

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  7. The value of (cos3theta)/(2cos2theta-1) is equal to (a) costheta (b) ...

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  8. The value of cos^4theta+sin^4theta-6cos^2theta is (a) cos2theta (b) s...

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  9. Prove that: sin(pi/10)+sin((13pi)/10)=-1/2

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  10. If tan(pi//4+theta)+""tan(pi//4-theta)=lambdasec2theta,t h e nlambda= ...

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  11. Prove that: (1+cos4x)/(cot x-tanx)=1/2sin4x

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  12. Prove that: (cos7x-cos8x)/(1+2cos5x)=cos2x-cos3x

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  13. To prove (cos5x+cos4x)/(1-2cos3x)=-cos2x-cosx

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  14. If tantheta= t, then tan2theta+sec2theta is equal to (a) (1+t)...

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  15. Prove that: "cot"pi/(24)=sqrt(2)+sqrt(3)+sqrt(4)+sqrt(6)

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  16. (sec8A-1)/(sec4A-1) is equal to (A) (tan2A)/(tan8A) (B) (tan8A)/(t...

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  17. If A=2sin^2theta-cos2theta,t h e nA lies in the interval (a) [-1,3] (...

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  18. Prove that (tan3x)/(tanx) never lies between 1/3a n d3 .

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  19. The value of (cot (x/2)-t a n (x/2))^2(1-2tanxcot2x) is (a)1 (b) 2 (c)...

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  20. Prove that cos^3A+cos^3(120^0+A)+cos^3(240^0+A)=3/4cos3A

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