Here,
`f_1(t)=sin\ t*{u(t)-u(t-pi)}`
and the period, `p=pi`.
`ccL{f_1(t)}`
`=ccL{sin\ t*(u(t)-u(t-pi))}`
`=ccL{sin t*u(t)}+ccL{sin(t-pi)*u(t-pi)}`
`=1/(s^2+1)+(e^(-pis))/(s^2+1)`
`=(1+e^(-pis))/(s^2+1)`
So the Laplace Transform of the periodic function is given by:
`ccL{f(t)}=(1+e^(-pis))/((s^2+1)(1-e^(-pis))`