Hi all,

I need help with the following task:

Calculate

∫∫ ln(1+x^2+y^2) dxdy

D

where D is: (x,y); 1 <=x^2+y^2<=2

(<= means bigger than or equal to)

I think I should use polar coordinates where

x= r cos §

y= r sin §

Then I get:

∫∫ ln(1+r^2)

∫ dr goes from 1 to 2

∫ d§ goes from 0 to 2 pi

But what is the integral of ln(1+r^2)?

I really need help,

thanks!