The volume of the solid obtained by rotating the region bounded byy=x2,y=5x,about the linex=5can be computed using the method of washers via an integral

V=ab ? dx dy

with limits of integrationa= andb= . The volume of this solid can also be computed using cylindrical shells via an integral

V= ? dx dy

with limits of integration= and= . In either case, the volume isV= cubic units.