Let $U \subset \mathbb{R}^n$ be open and let $f:U \to \mathbb{R}$ and $h:\mathbb{R}\to \mathbb{R}$ be differentiable functions.
How can I prove the following equation? \nabla{(h\circ f)}(P)=h'(f(P))\nabla f(P)
Let $U \subset \mathbb{R}^n$ be open and let $f:U \to \mathbb{R}$ and $h:\mathbb{R}\to \mathbb{R}$ be differentiable functions.
How can I prove the following equation? \nabla{(h\circ f)}(P)=h'(f(P))\nabla f(P)