if-u-f-x-y-where-x-rcos-y-r-sin-prove-u-x-2-u-y-2-u-r-2-1-r-u-2-

Question Number 88015 by M±th+et£s last updated on 07/Apr/20

i f u = f (x, y) w h e r e x = r c o s (θ), y = r s i n (θ)

p r o v e

{(\frac{\partial u}{\partial x})}^{2} + {(\frac{\partial u}{\partial y})}^{2} = {(\frac{\partial u}{\partial r})}^{2} + \frac{1}{r} {(\frac{\partial u}{\partial θ})}^{2}