Question

if U=log(x^2+y^2),show that d^2u/dx^2 +d^2u/dy^2 =0​

Answer 1

u=log(x2+y2+z2)21

u=21log(x2+y2+z2)

⇒2u=log(x2+y2+z2)

Differentiating w.r.t. 'x' on both sides, we get

2dxdu=x2+y2+z21⋅(2x)

⇒dxdu=x2+y2+z2x

dx2d2u=(x2+y2+z2)2(x2+y2+z2)(dxd

Step-by-step explanation:

I HOPE it's HELPFUL for you

Answer 2

Answer:

hi mate

your answer is in attachment

hope it works out