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Prove that: cos20^@+cos100^@+cos140^@=0....

Prove that: `cos20^@+cos100^@+cos140^@=0`.

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JBD PUBLICATION-MODEL PAPER (11)-EXERCISE
  1. If f(x)=(x-4)/(2sqrt3), then f'(1) is equal to?

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  2. If A and B are two events, the probability that exactly one of them oc...

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  3. Prove that: cos20^@+cos100^@+cos140^@=0.

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  4. If tan3A=(3 tan A+k tan^(3)A)/(1-3 tan^(2)A), then k is equal to

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  5. Evaluate: [i^20+(1/i)^26]^3.

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  6. Using Binomial theorem prove that:(1.1)^10000> 10000

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  7. Write the general term in the expansion of (x^(2)-yx)^(12), x ne 0

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  8. Let (4, 2), B (6, 5) and C (1, 4) be the vertices of triangleABC. :- ...

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  9. Verify by the method of contradiction that sqrt7 is irrational.

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  10. Find the component statement of the following and check whether they a...

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  11. Assume that P(A) = P(B). Show that A = B

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  12. If AxxB={(a,x),(a,y),(b,x),(b,y)}. Find A and B

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  13. Prove that : sin (A + B) sin (A - B) = sin^2A- sin^2B.

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  14. Using principle of mathematical induction, prove that: 1/1.2.3+1/2.3.4...

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  15. Determine the number of ways of choosing 5 cards out of a deck of 52 c...

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  16. A question paper has two parts: Part A and Part B. each part containin...

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  17. A.M. between two numbers is 10 and their G.M is 8. Find the numbers.

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  18. The sum of first four terms of an A.P is 56. the sum of last four term...

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  19. If p is the length of perpendicular from the origin to the line whose ...

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  20. Find the equation of ellipse with major axis along x-axis passes throu...

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