Hi everybody,
I don't know how to find $\displaystyle S=\sum_{k=0}^n cos(k \alpha)$ without using complex. Can you help me please find an alternative way of doing it?
And thanks.
Hi everybody,
I don't know how to find $\displaystyle S=\sum_{k=0}^n cos(k \alpha)$ without using complex. Can you help me please find an alternative way of doing it?
And thanks.