Product rule for the Laplacian
= Product rule for the Laplacian
For twice differentiable scalar fields,
$$
\nabla^2(fg)
=f\nabla^2g+2\nabla f\mathbin\cdot\nabla g
+g\nabla^2f.
$$
= Product rule for the Laplacian
For twice differentiable scalar fields,
$$
\nabla^2(fg)
=f\nabla^2g+2\nabla f\mathbin\cdot\nabla g
+g\nabla^2f.
$$