Find the Laplacian of f(x,y)=ln(x2+y2)f(x, y) = \ln(x^2 + y^2)f(x,y)=ln(x2+y2).
000
1x2+y2\frac{1}{x^2+y^2}x2+y21
4(x2+y2)2\frac{4}{(x^2+y^2)^2}(x2+y2)24
2ln(x2+y2)2\ln(x^2+y^2)2ln(x2+y2)