. Let f(x) be a function of period 27 such that f(x)=\left\{\begin{array}{lll}

0 & \text { if } & -\pi \leq x<0 \\

x & \text { if } & 0 \leq x<\pi

\end{array}\right. f(x+2 \pi)=f(x) a) Sketch a graph of f(x) in the interval -37 < x < 3m. (b) Calculate the Fourier series for f(x) in the interval - < x < and hence write the terms up to-and including n = 5.