verify that each given function is a solution of the given partial differential equation.

uxx+uyy=0;u1(x,y)=cosxcoshy,u2(x,y)=ln(x2+y2)

verify that each given function is a solution of the given partial differential equation.

uxx+uyy=0;u1(x,y)=cosxcoshy,u2(x,y)=ln(x2+y2)