30. Find the volume of the solid obtained by rotating around the line y−axis the regionboundedbyy=x2 andx=y2.

31. Find the area of the region bounded by the curves y = sinx, y = cosx, x = 0 and x = π/2.

32. Find the volume of the solid obtained by rotating around the x−axis the region√√

boundedbyy= 1+x2,thex−axis,they−axisandx= 3.

33. Set up, but do not evaluate, an integral for the volume of the solid obtained by

rotating about the y-axis the region bounded by the curves

34. Find the volume of the solid obtained by rotating about the x-axis the region

bounded by the curves y = x3, the y-axis and y = 2.

35 Find the volume of the solid obtained by rotating about the y-axis the region

bounded by the curves y = 2x2 −x3, and y = 0.