$ x(t) = \sqrt(t) $
$ x(t) = \cos(t) + \jmath\sin(t) $
$ E_\infty = \int_{-\infty}^\infty |x(t)|^2\,dt $
$ =\int_{-\infty}^\infty |\sqrt(t)|^2\,dt $ $ =\int_0^\infty \t\,dt $
