To find volume of solid of revolution The volume of a solid generated by revolving about the horizontal line y=2 the region bounded by $y^{2}\leq2x$, $x\leq 8$ and $y\geq 2$.
I have figured out the area to be revolved. But I do not know how to do disk method or washer method here.
Thanks you so much

Your function that describes the solid is $f(x) = \sqrt{2x} - 2$. Integrate the square of this function over $ \sqrt{2x} = 2 \Leftrightarrow x = 2$ to $ x = 8$ to get the volume:
$$V = \pi* \int_{2}^{8}  (\sqrt{2x} - 2)^2dx $$
