Question-
$R$ is the region bounded by $y=\sqrt{x}$ and $y=\frac{x}{2}$ and this region is rotated around $x=4$. What is the volume?
My attempt
$$\left|\pi\int_0^2 ((4-2y)^2-(4-y^2)^2) \right| \, dy$$
I got $20.106$
However, Wolfram alpha received something else as in the photo posted
Am I doing something wrong?