Calculate volume in a 3D sort of space using cartesian coordinates Find the volume bounded by the cylinder $x^2 + y^2 = 1$, the planes $x=0, z=0, z=y$ and lies in the first octant. (where x, y, and z are all positive)

Or by using the polar coordinates instead as below: $$\int_{r=0}^1\int_{\theta=0}^{\pi/2}\int_{z=0}^{y\sin(\theta)}rdzd\theta dr=1/3$$

