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Homework Help: Should my volume be negative in this case

  1. Oct 9, 2007 #1
    I have not run into a volume problem that returned a negative value as of yet...until now.

    I have the following problems:
    Find the volume when the region, in the FIRST quadrant,bounded by y=x^2; y=2-x; and x=0 is:
    revolved around the x-axis and then revolved around the line y=2.

    (a) For the x-axis I got:

    (b) and for around y=2 I got

    But I have my doubts about the latter.

    Any help is appreciated,
    Last edited: Oct 9, 2007
  2. jcsd
  3. Oct 9, 2007 #2
    How about this question: for part (b), am I using the right integral? To revolve around y=2, that is?
  4. Oct 9, 2007 #3
    I give up. Usually Dick is yelling at me by now:frown:
    Last edited: Oct 10, 2007
  5. Oct 10, 2007 #4
    Are my bounds reversed on part b? Since the line being rotated about is located "ABOVE" the region being rotated? I know it needs to be positive.
    Last edited: Oct 10, 2007
  6. Oct 10, 2007 #5
    This one must be too tough or something.
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