I have a problem with the convolution of two signals:
$$x_{1}(t) = e^{2t}*u(-t)$$ $$x_{2}(t) = u(t-3)$$
$$x_1 \mathbin{\mathrm{(conv)}} x_2 = \int_{-\infty}^{+\infty} x_2(\tau) * x_1(t-\tau) \, d\tau$$
My usual way is, as the integral says, leave one function as it is and mirror the other one. In my previous task there was no intersection after the mirroring and I could shift the mirrored function until they both intersect for the first time and this was my integration border. But in this task, if I mirror $x_{2}$, I get a function, that is already intersecting $x_{1}$, because it runs exponentially to $0$ for large $\tau$.
How can I do this convolution?
