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If cos alpha+cos beta=0=sin alpha+sin be...

If `cos alpha+cos beta=0=sin alpha+sin beta`, then `cos 2 alpha+cos 2beta` is equal to

A

`3pi//4`

B

`pi//4`

C

`pi//6`

D

`pi//8`

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AAKASH SERIES-TRIGONOMETRIC EQUATIONS-Practice Exercise
  1. If tantheta+sectheta=sqrt(3), then the principal value of (theta+(pi)/...

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  2. If 3costheta+4sintheta=lambda has a solution find the range of lambda.

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  3. If costheta-sintheta=1, then theta

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  4. If tantheta+sectheta=sqrt(3), then the principal value of (theta+(pi)/...

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  5. The solution set of cos5theta=cos3theta is (ninz)

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  6. The solution set of sin(x+(pi)/4)=sin 2x

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  7. Sinx=2sinxcos2x is satisfied if x belongs to

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  8. All the values of x satisfying sin 2x + sin 4x = 2 sin 3x are

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  9. The solution set of cos5theta=cos3theta is (ninz)

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  10. The general solution of sin^(2)x-2 cos x +(1)/(4)=0 is

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  11. If (1)/(6) sin theta, cos theta and tan theta are in geometric progres...

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  12. If tanax-tanbx=0 then the solutions of x form

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  13. Solution of secqx+secpx=0 form AP with common difference

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  14. If cos alpha+cos beta=0=sin alpha+sin beta, then cos 2 alpha+cos 2beta...

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  15. If (cot^(-1)x)^(2)-7(cot^(-1)x)+10 gt 0, then x lies in the interval

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  16. (cos3theta)/(2cos2theta-1)=

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  17. Statement-I: For ninz,2sin^(2)theta=cos2thetaimplies(theta)/(2)=(npi...

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  18. Statement-I: x inQ(1) and cosx+cos3x=cos2x then x=30^(@)or45^(@) Sta...

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  19. Match the trigonometric equations from List I to solutions in List II ...

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  20. The most general value of theta satisfying both the equations sintheta...

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