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Find sum(r=1)^(10) cos^(3) rpi/3....

Find `sum_(r=1)^(10) cos^(3) rpi/3`.

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Find sum_(r=1)^(10) (r+2)(3r+1).

The value of sum_(r=0)^(10)cos^(3)((r pi)/(3)) is

The value of sum_(r=0)^(10)cos^(3)((r pi)/(3)) is equal to (a) (1)/(4) (b) (1)/(8)(c)-(1)/(4)(d)-(1)/(8)

sum_(r=1)^(10) (4r-3)^(2) =

Prove that sum_(r=1)^(10) = sin^(2) rpi/18 =5 .

If A=sum_(r=1)^(3)"cos"(2r pi)/(7) and B=sum_(r=1)^(3)"cos"(2^(r )pi)/(7) then :

If A= sum _(r=1)^(3)"cos"(2r pi)/(7) and B=sum_(r=1)^(3)"cos"(2^(r )pi)/(7) , then :

sum_(r=1)^(n)(3^(r)-r)=

sum_(r=1)^(n-1)cos^(2)""(rpi)/(n) is equal to

If n be integer gt1, then prove that sum_(r=1)^(n-1) cos (2rpi)/n=-1

A DAS GUPTA-Circular Functions, Identities -Exercise
  1. Prove that sum(r=1)^(10) = sin^(2) rpi/18 =5.

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  2. Sum the series: sin alpha - sin 2alpha + sin 3alpha - sin 4alpha + .....

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  3. Find sum(r=1)^(10) cos^(3) rpi/3.

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  4. Sum: sqrt(1 + sin 2alpha) + sqrt(1 + sin 4alpha) + sqrt(1 + sin 6alpha...

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  5. Prove that sin^(2) 12^circ + sin^(2)21^circ + sin^(2)39^circ + sin^(2)...

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  6. If A + B + C = pi, prove that cos A cosec B cosec C + cos B cosec C c...

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  7. Prove that in a triangle ABC, sin^(2)A - sin^(2)B + sin^(2)C = 2sin A...

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  8. Prove that in a triangle ABC, sum (cot B+ cotC)/(tan B + tan C) =1.

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  9. If A +B+C = 180^circ, prove that cos A/2+ cos B/2 +cos C/2 = 4cos (p...

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  10. If alpha + beta- gamma= pi, prove that sin^(2)alpha + sin^(2)beta - s...

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  11. If alpha + beta + gamma = 2 theta, prove that cos theta + cos(theta- ...

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  12. If A + B + C = pi, show that cot A + sinA/(sin B sin C) = cot B + sin...

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  13. If A + B + C = 0, prove that sum sin 2A = 2sum sin A * (1 + sum cos A...

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  14. Prove that tan(x - y) + tan(y - z) + tan(z - x) = tan(x - y) *tan(y -...

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  15. If alpha + beta + gamma + delta = 2pi then prove that sum tan alpha =...

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  16. If cos(beta - gamma) * cos(gamma - alpha)* cos(alpha - beta) + 1 = 0 ...

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  17. If x + y + z = xyz, prove that x(1 -y^(2)) (1- z^(2))+ y(1- z^(2))(1- ...

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  18. If x + y + z = xyz, prove that (3x -x^(3))/ (1-3x^(2)) + (3y -y^(3))/(...

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  19. If A + B + C = pi then show that cot theta = cot A + cot B + cot C ⇔ s...

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  20. If theta = pi/7 prove that cos theta* cos 2theta * cos 3theta = 1/8

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