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cos1+cos2+cos3+...+cos180...

`cos1+cos2+cos3+...+cos180`

A

1

B

0

C

2

D

`-1`

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The correct Answer is:
D
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OBJECTIVE RD SHARMA-TRIGONOMETRIC RATIOS AND IDENTITIES-Exercise
  1. If cosA+cosB+cosC=0, then cos3A+cos3B+cos3C is equal to

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  2. Minimum value of cos2theta+costheta for all real value of theta is

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  3. cos9^@-sin9^@=

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  4. If y=(sin 3theta)/(sintheta), theta nen pi, then

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  5. If tan(picostheta)=cot(pisintheta),0lt thetalt(3pi)/(4), then sin(thet...

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  6. If tan(picostheta)=cot(pisintheta),"then the value of"sin(theta+(pi)/(...

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  7. 1+sinx+sin^(2)x+..."to"oo=2sqrt3 + 4, if x = ?

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  8. If sin(x-y)=cos(x+y)=1/2, the value of x and y lyingbetween 0^(@)and 9...

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  9. If alpha and beta be between 0 and (pi)/(2)and if cos(alpha+beta)=(12)...

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  10. If tan (alpha/2) and tan beta/2are the roots of the equation 8x^2-26x+...

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  11. 2x^(2) + 3x - alpha - 0 " has roots "-2 and beta " while the equation ...

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  12. If A+B+C=0, then the value of sum cot (B+C-A) cot (C+A-B) is equal to

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  13. In (0,pi//2)tan^(m)x+cot^(m)x attains

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  14. For -(pi)/(2)lttheta(pi)/(2),(sintheta+sin2theta)/(1+costheta+cos2thet...

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  15. If y tan (A+B+C) =x tan (A+B-C) = gamma then tan 2C=

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  16. Which of the following is not the qyadratic equation whose roots are c...

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  17. cos alphasin(beta-gamma)+cosbetasin(gamma-alpha)+cos gammasin(alpha-be...

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  18. sin47^(@)-sin25^(@)+sin61^(@)-sin11^(@)=

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  19. cos1+cos2+cos3+...+cos180

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  20. The value of (tan7 0^0-tan2 0^0)/(tan5 0^0)=

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