The first five terms in the Fourier series of a periodic waveform are

\[
\begin{aligned}
v(t)= & -12.5+25\left[\frac{\pi}{4} \cos (2 \pi \times 500 t)-\frac{1}{3} \cos (2 \pi \times 1000 t)ight. \\
& \left.-\frac{1}{15} \cos (2 \pi \times 1500 t)-\frac{1}{35} \cos (2 \pi \times 2500 t)ight] \mathrm{V}
\end{aligned}
\]

(a) Find the period and fundamental frequency in \(\mathrm{rad} / \mathrm{s}\) and Hz. Identify the harmonics present in the first five terms.

(b) Use Excel to plot two periods of \(v(t)\).

(c) Identify the symmetry features of the waveform.