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If x + 1/x = 2cos theta, then for any in...

If `x + 1/x = 2cos theta`, then for any integer `n, x^(n) + 1/x^(n)` =

A

`2 cos n theta`

B

`2 sin n theta`

C

`2i cos n theta`

D

`2i sin n theta`

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WB JEE PREVIOUS YEAR PAPER-QUESTION PAPER 2011-MULTIPLE CHOICE QUESTIONS
  1. If alpha and beta are the roots of the equation x^2 + x + 1=0 , then...

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  2. For the real parameter t, the locus of the complex number: z=(1-t^(2...

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  3. If x + 1/x = 2cos theta, then for any integer n, x^(n) + 1/x^(n) =

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  4. If omega ne 1 is a cube root of unity, then the sum of the series S...

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  5. If log(3)x + log(3)y =2 + log(3)2 and log(3)(x+y) =2, then

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  6. If log(7)2 = lambda, then the value of log(49) (28) is:

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  7. The sequence log a, log (a^(2)/b), log (a^(3)/b^(2)) is:

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  8. If in a triangle ABC, sin A, sin B, sin C are in A.P, then

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  9. |{:(a-b, b-c, c-a),(b-c, c-a, a-b),(c-a, a-b, b-c):}|=

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  10. The area enclosed between y^(2) = x and y=x is:

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  11. Let f(x) = x^(3) e^(-3x) , x gt 0. Then the maximum value of f(x) is:

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  12. The area bounded by y^(2) = 4x and x^(2) = 4y is:

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  13. The acceleration of a particle starting from rest moving in a straight...

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  14. The solution of: (dy)/(dx) = y/x + tan y/x is:

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  15. Integrating Factor (I.F). Of the differential equation: (dy)/(dx) -...

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  16. The differential equation of y=ae^(bx) (a & b are parameters) is:

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  17. The value of: lim(n to infty) sum(r=1)^(n) r^(2)/(r^(3) + n^(3)) is:

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  18. The value of int(0)^(pi) sin^(50)x cos^(49) x dx is:

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  19. int 2^(x) [f'(x) + f(x) (log 2)] dx is

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  20. Let f(x) = tan^(-1) x. Then f'(x) + f''(x) is =0, when x is equal to:

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