# Double integral volume problem

1. Nov 18, 2014

### nate9519

1. The problem statement, all variables and given/known data
find the volume of the solid below the plane z = 4x and above the circle x^2 + y^2 = 16 in the xy plane

2. Relevant equations

3. The attempt at a solution
This totally confused me. I didn't think the plane z = 4x sat above the xy plane. If that is true then there would be no solid between the two graphs. I ended up putting zero for the answer. was I right or wrong

2. Nov 18, 2014

### Staff: Mentor

Part of the z = 4x plane lies above the xy plane. Did you draw a sketch of the plane and the circle?

3. Nov 19, 2014

### Zondrina

$$\iint_R z \space dA = \iiint_V \space dV$$

$$\iiint_V \space dV = \iint_R \int_0^z \space dzdA$$

;)

Polar co-ordinates.