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CALCULUS: HELP NEEDED WITH VOLUME PROBLEM

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Gordon Wong

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Aug 30, 1993, 11:15:29 PM8/30/93
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I've tried everything ... I need help!

The area bounded by the curve y = x^2 and the line y = 4 is rotated about the
line x = 2. What is the volume generated?

I have the answer but I can't seem to get it. Maybe the answer is wrong? How
do you solve it?

Susan D. Strickland

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Aug 31, 1993, 8:57:24 AM8/31/93
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In article <28...@mindlink.bc.ca> Gordo...@mindlink.bc.ca (Gordon Wong)
writes:

Gordon-
The best way to solve it is by using cylinders (shells).
-Sue-
--
********************************************************
Susan R. Strickland * "If at first *
St. Mary's College of Maryland * you do succeed - *
St. Mary's City, MD 20686 * try to hide *
sstr...@oyster.smcm.edu * your astonishment." *
********************************************************

s142...@umassd.edu

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Sep 10, 1993, 2:17:13 PM9/10/93
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My guess would be that you have to take into consideration two curves.
In order to find the volume generated by x^2 and by 4, you subtract (i.e. x^2-4).
Also, the disk method would be easiest to go about it. Thus the volume would then be:
2
/
pi | (g(x))^2 dx, where g(x)=x^2-4
/
0

Brian Colby/Umass Dartmouth/1993

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