jax test

$E=\frac{-{{\hbar }^{2}}}{2m}{{\nabla }^{2}}\psi $

$P=P\left( \rho,\theta,\varphi \right)$

$\delta x=\frac{\partial x}{\partial {{q}_{1}}}\delta {{q}_{1}}+\frac{\partial x}{{{q}_{2}}}\delta {{q}_{2}}=\cos \theta \delta r-r\sin \theta \delta \theta $