So we write as. In addition,the intervalon the -axis becomes Thus
Simplifying,
With the aid of -substitution,let
ReviewQuestions
In problems#1–3find the area of the surfacegeneratedby revolvingthe curveaboutthe x-axis.
In problems#4–6find the area of the surfacegeneratedby revolvingthe curveaboutthe -axis.
- Showthat the surfacearea of a sphereof radius is.
- Showthat the lateralarea of a right circularconeof height and baseradius is