$ x(t)=tu(t) $
$ E_\infty = \int_{-\infty}^\infty |tu(t)|^2\,dt) $
$ E_\infty = \int_{0}^\infty t^2\,dt) $
$ E_\infty =\frac{t^3}{3}\bigg]_0^\infty) $
$ E_\infty =\infty-0 = \infty $
$ P_\infty = lim_{T \to \infty} \ \frac{1}{2T} \int_{-T}^T |tu(t)|^2\,dt $
$ P_\infty = lim_{T \to \infty} \ \frac{1}{2T} \int_{0}^T t^2\,dt $
$ P_\infty = lim_{T \to \infty} \ \frac{1}{2T} \frac{t^3}{3}\bigg]_0^\infty $
