Solve

$$\{\begin{array}{rl}& {y}^{\u2033}-3{y}^{\prime}+2y=g\\ & y(0)={y}^{\prime}(0)=0\end{array}$$

whereas

$$g(t)=\{\begin{array}{ll}0,& t>\pi \\ \mathrm{sin}t,& 0\le t\le \pi .\end{array}$$

$$\{\begin{array}{rl}& {y}^{\u2033}-3{y}^{\prime}+2y=g\\ & y(0)={y}^{\prime}(0)=0\end{array}$$

whereas

$$g(t)=\{\begin{array}{ll}0,& t>\pi \\ \mathrm{sin}t,& 0\le t\le \pi .\end{array}$$