Let be $u\in W^{m,p}(\mathbb{R^n})$. Show that if a one partial derivate of $u$ is zero, then $u = 0$.
How I can be able to start this proof?
Let be $u\in W^{m,p}(\mathbb{R^n})$. Show that if a one partial derivate of $u$ is zero, then $u = 0$.
How I can be able to start this proof?