Originally Posted by

**NothingButSmiles** I'm supposed to find the volume of a graph. The equation of the graph is y=5-2cos(2x). The domain is from 0 to 3$\displaystyle pi$/4. I have tried a million different ways, using integrals to figure this out, unfortunately, every single answer I get is wrong. I've tried u substitution as well as a few other methods, but I do not get a consistent area. I also don't understand how to get the volume from there, especially since if you rotate it, the radius wouldn't be constant.

Answer choices are:

a) 10pi+20.25pi^2

b).5pi^2

c).25

d)1/9

e)8pi + 21pi^2

Help pretty please.

- NothingButSmiles