What is the volume of:

y=square root(x), y=1, x=4

revolved about the x-axis?

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- Aug 2nd 2009, 01:09 PMchevy900ssVolume of a solid
What is the volume of:

y=square root(x), y=1, x=4

revolved about the x-axis? - Aug 2nd 2009, 01:34 PMo_O
Use the disc method. We create a disc by making a cross section perpendicular to the x-axis. The volume is then given by $\displaystyle \int_a^b A(x) dx$ where $\displaystyle A(x)$ is the area of our disc and $\displaystyle x= a, \ b$ are our bounds.

More here: Volume with Rings - Aug 2nd 2009, 01:41 PMchevy900ss
is that the same as

V=(pie)interval from a to b((f(x)^2)-(g(x)^2) dx - Aug 2nd 2009, 01:44 PMo_O
Yes. What is our $\displaystyle f(x)$ and $\displaystyle g(x)$ in this case?

- Aug 2nd 2009, 01:47 PMchevy900ss
f(x)=square root of x

g(x)=1 - Aug 2nd 2009, 01:52 PMchevy900ss
So is the answer 9pie/2

- Aug 2nd 2009, 01:56 PMo_O
(Yes)

- Aug 2nd 2009, 02:05 PMchevy900ss
awesome thanks

- Aug 2nd 2009, 03:49 PMDeMath
Also see picture

http://s15.radikal.ru/i188/0908/3f/7b369fcbaa45.png