Use the Laplace transform table to find $f(t)=\int_{0}^{t} e^{-\tau} \sin (t-\tau) d \tau .$ Hint: In $L 34$ let $g(t)=e^{-t}$ and $h(t)=\sin t,$ and find $G(p) H(p)$ which is the Laplace transform of the integral you want. Break the result into partial fractions and look up the inverse transforms.