- #1

yungman

- 5,726

- 242

[tex] \frac{x}{r} \frac{\partial u}{\partial x} + \frac{y}{r} \frac{\partial u}{\partial y} +\frac{z}{r} \frac{\partial u}{\partial z} \;=\; \frac{\partial u}{\partial r} [/tex]

Where

[tex] r=\sqrt{x^2+y^2+z^2}[/tex]

This is not a homework problem.

Thanks