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If n-1,2,3,dot,t h e ncosalpha"cos"2alph...

If `n-1,2,3,dot,t h e ncosalpha"cos"2alpha"cos"4alphacos2^(n-1)alphai se q u a lto` `(sin2nalpha)/(2nsinalpha)` (b) `(sin2^nalpha)/(2^n"sin"2^("n"-1)alpha)` (c) `(sin4^(n-1)alpha)/(4^(n-1)sinalpha)` (d) `(sin2^nalpha)/(2^n"sin"alpha)`

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RD SHARMA ENGLISH-TRIGONOMETRIC RATIOS OF MULTIPLE AND SUBMULTIPLE ANGLES-All Questions
  1. If n-1,2,3,dot,t h e ncosalpha"cos"2alpha"cos"4alphacos2^(n-1)alphai s...

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  2. If 5 sinalpha=3"sin"(alpha+2beta)!=0, then tan(alpha+beta) is equal ...

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  3. If tantheta=a/b ,then bcos2theta+asin2theta is equal to (a) a (b) b ...

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  4. Prove that: cos^2A+cos^2(A+(2pi)/3)+cos^2(A-(2pi)/3)=3/2

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  5. If 2tanalpha=3t a nbeta,t h e ntan(alpha-beta)= (a) (sin2beta)/(5-cos...

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  6. Prove that: sin^2 24^0-sin^2 6^0=(sqrt(5)-1)/8

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  7. Prove that: cos36^0=(sqrt(5)+1)/4 .

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  8. Prove that: sin^2 24^0-sin^2 6^0=(sqrt(5)-1)/8

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  9. Prove that: cos18^0=(sqrt(10+2sqrt(5)))/4 .

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  10. If t a ntheta/2=sqrt((1-e)/(1+e))tan(alpha/2), then cosalpha= (a) 1...

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  11. If cos2x+2cosx=1t h e n ,(2-cos^2x)sin^2x is equal to

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  12. If alpha and beta are acute angles satisfying cos2alpha=(3cos2beta-1)/...

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  13. Prove that: cos^2A+cos^2(A+pi/3)+cos^2(A-pi/3)=3/2

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  14. Prove that: cos^(2)48^(@)-sin^(2)12^(@)=(sqrt(5)+1)/(8)

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  15. The value of (sin5alpha-sin3alpha)/(cos5alpha+2cos4alpha+cos3alpha) is

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  16. If costheta=1/2(a+1/a),cos3theta=lambda(a^3+1/(a^3)), t ...

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  17. Prove that: t a nA+tan(60^0+A)-t a n(60^0-A)=3t a n3A

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  18. If t a n^2theta=2tan^2phi+1 , prove that cos2theta+sin^2phi=0.

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  19. If theta=pi/(2^n+1) , prove that: 2^ncosthetacos2thetacos2^2thetacos2^...

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  20. Prove that: cotA+"cot"(60^0+A)-cot(60^0-A)=3cot3A

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