Question

If u=log⁡(x^2+y^2 )+tan^(-1)⁡(y/x) ,Show that (∂^2 u)/(∂x^2 )+(∂^2 u )/(∂y^2 )=0 .

Answer 1

Answer:

If u=log(x

2

+y

2

+z

2

), verify

∂x∂y

∂

2

u

=

∂x∂y

∂

2

u