Thread: Summing a Trig function

can anyone help me sum this summation?



thanks

I'm too lazy to try to work it out, but my first thought is to use Euler's formula and keep the imaginary components and see if it works into a sum with a ready answer. As my initial guesses usually go though... I'm probably wrong.

Originally Posted by william

I'm too lazy to try to work it out, but my first thought is to use Euler's formula and keep the imaginary components and see if it works into a sum with a ready answer. As my initial guesses usually go though... I'm probably wrong.

It will work. The exponentials form a finite geometric sum. It is slightly tedious to then separate the real and imaginary parts.