Chapter 7.9, Problem 15P

Given $f(x)=x$ for $0<x<1$, sketch the even function $f_c$ of period 2 and the odd function $f_x$ of period 2, each of which equals $f(x)$ on $0<x<1.$ Expand $f_c$ in a cosine series and $f_x$ in a sine series.