Please help 6,7

Evaluate the iterated integral by converting to polar coordinates 9(x + y) dx dy Use spherical coordinates. Evaluate (X2 + y2) dV, where E lies between the spheres x2 y2 + z2 = 9 and x2 + y2 + z2 = 25.

## Answer

Consi der the following double integral From the above double integral Now, the lower limitis rcos θ r sin θ tan θ-1 -arctan(1) IT 4 And, the upper limit is Now, the required triple integral is es.or sinado 2-(0-1) Hence, the required double integral is [ J (x+ »)rzhy-