# Math Help - Volume of a sphere

1. ## Volume of a sphere

i have a question that asks for the volume of the sphere using "Volume of Solids of Revolution" i know that the volume formula of a sphere is 4/3*pi*r^3 but how do i get to that because when i integrate the area, i come up with 1/3*pi*r^3. i just need to know how to go from the integral of pi*r^2 to 4/3*pi*r^3.

thanks in advance

2. Can I see the full integral please?

3. Can I see the full integral please?
don't worry, i have figured it out. need to find the integral of r^2=x^2+y^2, not pi*r^2. thanks anyway