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Homework Help: Area in between two curves

  1. May 28, 2012 #1
    Find the area of the region bounded by the following curves:

    y=x2-5x and y=3-x2

    Answer:

    So, using simultaneous equations I found the points of intersection (x = -0.5 and x = 3). The book agrees with me on that.

    I then performed the following:

    3-x2-(x2-5x)

    = -2x2+5x+3

    I then integrated that:

    ((-2/3)*x3)+((5/2)*x2)+3x

    I then subtracted the result when I substitute -0.5 from the result I get when I substitute 3. The book claims the answer is 2.655 but, no matter how hard I try I keep getting (271/24)

    Can anyone help me here please?

    Thanks!
     
  2. jcsd
  3. May 28, 2012 #2

    LCKurtz

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    The work you showed so far is correct. Unfortunately I get 343/24 = 14.29 which doesn't agree with either of yours. Your book's answer is obviously wrong; clearly too small for the area enclosed.
     
  4. May 28, 2012 #3
    Hi! Thanks a lot for your response. I must be making some calculation error! When I try using the graphic calculator to find the integral it gives me 14.29, so, yeah, you should be right. I will try again.

    Thanks once again,
    Peter
     
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