**Exercise:** Sketch the region enclosed by the given curves. Decide whether to integrate with respect to x or y. Draw a typical approximating rectangle and label its height and width. Then find the area of the region.

4x+y^2=12, x=y

**Exercise:** Find the volume of the solid obtained by rotating the region bounded by the given curves about the specified line. Sketch the region, the solid, and a typical disk or washer. x=2\sqrt{y}, x=0, y=9; about the y-axis.