Chapter 7.9, Problem 10P

Each of the functions in Problems 5 to 12 is given over one period. For each function, sketch several periods and decide whether it is even or odd. Then use (9.4) or (9.5) to expand it in an appropriate Fourier series. 10. $f(x)=\left|x\right|,-\frac{\pi }{2}<x<\frac{\pi }{2}$.