evaluate `[[cos(pi)/(5)-i sin(pi)/(5)]]^(-5)`

The value of cos(pi)/(5)cos.2(pi)/(5)cos4(pi)/(5)cos8(pi)/(5)=

If alpha=cos((2 pi)/(5))+i sin((2 pi)/(5)), then find the value of alpha+alpha^(2)+alpha^(3)+alpha^(4)

Evaluate sin((pi)/(n))+sin((3 pi)/(n))+sin((5 pi)/(n))+ to n terms.

Convert the complex number 3(cos(5(pi)/(3))-i sin((pi)/(6))) into polar form.

Let z = a("cos"(pi)/(5) + "i sin" (pi)/(5)),a in R, |a| lt 1 , then S = z^(2015) + z^(2016) + z^(2017) + ... equals

prove that cos[(pi)/(5)]-cos[(2 pi)/(5)]=(1)/(2)

The value of cos((pi)/(5))+cos((13 pi)/(5)) is equal to

Find the amplitude of sin(pi)/(5)+i(1-cos(pi)/(5))

Evaluate: sin^(-1)(sin(3 pi)/(5))

Find the value of cos""(pi)/(12)(sin""(5pi)/(12)+cos""(pi)/(4))+sin""(pi)/(12)(cos""(5pi)/(12)-sin""(pi)/(4)) .