Ok
the solution here
Attachment 11591
Attachment 11592
but there is a mistake (3r+3)r dzdrd(theta) in the integral after I convert it polar the right is (3r^2+3)r dzdrd(theta)
Ok
the solution here
Attachment 11591
Attachment 11592
but there is a mistake (3r+3)r dzdrd(theta) in the integral after I convert it polar the right is (3r^2+3)r dzdrd(theta)