### label which curves are which equation
area = ∫top curve-bottom curve, limits also in terms of x
volume =∫area ex: square is bh or b² is ∫(top-bottom)²
distance between curve= top-bottom, if you want the rate the distance changes then it's derivatives because they create pers.
if there's a crazy one where there is no top and bottom, then you'll have to switch things to y terms; area =∫right-left and do it from y to the y where they intersect. or you can break it up individually, keep it in x terms but now divide the region by the intersection point and add the two all in x.
use this method with the volume, you'll have to do the volume in both parts then.
with circles rotated around some y= value. your doing cross sections, so it would π∫(R-r). draw the line and make a perpendicular dashed line hitting both parts of the curve.