Find the volume of the solid bounbded by the graph of the eq

Find the volume of the solid bounbded by the graph of the equation z=9-x^2-y^2 and the xy-plane.

Using polar coordinates

z= 9-r^2 since (x^2 +y^2)= r^2
So we have int (9-r^2)r dr d from r= 0 to 3 and from 0 to 2

9/2 r^2 -r^4/4 from 0 to 3