Hello,
There are two series C = cosx + cos3x + cos5x +...+cos(2n-1)x
and S = sinx + sin3x + sin5x +...+sin(2n-1)x
I have summed the series and got C + iS = (cos2nx - 1 + isin2nx)/2isinx
(Not sure if that is right but looks like it?)
How would I find the modulus of C + iS? The answer is sin(nx)/sinx but I don't see how to get there which is why I'm unsure about getting the sum of the series correct. Also how would I find the argument of C + iS?
Thanks in advance