## anonymous 3 years ago Consider the solid obtained by rotating the region bounded by the given curves about the y-axis. Find the volume of this solid. y^2=4x x=y I don't know how to start!

1. cwrw238

the diagram looks something like this

2. anonymous

Always begin with a drawing, to see what is going on:

3. cwrw238

|dw:1359323354480:dw|

4. cwrw238

very rough of course!!!!

5. anonymous

@cwrw238: Geogebra is your friend ;)

6. anonymous

@Aenn88: do you know the Shell method?

7. cwrw238

geogebra? i must try that

8. anonymous

using cylindrical shells? i somewhat understand it in watching videos but I have a hard time applying it to another problem. i will use geogebra in the future! :)

9. anonymous

@ZeHanz

10. anonymous

See geogebra.org. First , remember if y²=4x then y=√(4x). Here r is x, and h is the length of the vertical difference of the two graphs: Cylindrical shells:$\int\limits_{0}^{4}2\pi r hdr=\int\limits_{0}^{4}2\pi x(\sqrt{4x}-x)dx$

11. anonymous

ok that makes sense..thank you