Given that: $$f(t)= \begin{cases} -1& \text{if } t<0 \\2 &\text{if } t\geq0 \end{cases}$$ and assuming that ${{\omega }_{0}}=$$\frac{2\pi}{T}$
How do I calculate the following integral? \begin{equation} a_0=\frac{2}{T}\int_{-T/2}^{T/2}f(t)\cos(2{{\omega }_{0}}t)~dt \end{equation}