Plotting partial sums of the fourier series

Question

I need to find and plot the fourier series of $\sin^{2}(x)$. I know that the Fourier Series for this function is clearly $\frac{1}{2} - \frac{1}{2} \cos(2x)$ which is the reduction formula for $\sin^2(x)$. but now how do i find the first, 5, 10 ... terms of the partial some and plot them?

Thanks in advance

Answer 1

The fourier expansion of $\sin^2(x)$ is $\frac 1 2 - \frac 1 2 \cos (2x)$ :D