Fuente TeX:

\frac{d}{dt} ( \frac{1}{2} m \dot{x}^2 + U(x) ) = 0 \\ \rightarrow \frac{1}{2} m \dot{x}^2 + U(x) = \frac{1}{2} m \dot{x}^2(0) + U(x(0)) = E