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Homework Help: Integrate sqrt problem

  1. Sep 6, 2005 #1
    Ok, I've been doing work for about 4 hours straight and I think my brain is fried. I know this is easy, it is just not working in my head.

    Anyway, the problem is this:

    Integrate the sqrt(4x) + sqrt(4x) on the interval 0 to 1

    I get, (8^3/2)/3 + (8^3/2)/3 but apparently this is not right. I'm probably forgetting something I'll hit myself in the head for :cry:. Any help though?

    Thx,
    MathGnome

    PS: This is not homework.
     
  2. jcsd
  3. Sep 6, 2005 #2
    I'm sorry, but I'm having trouble seeing what the problem is. Did you mean [itex]\int_{0}^{1}\left(\sqrt{4x}+\sqrt{4x}\right)dx[/itex]? That's what it looks like. If so, you can simplify before integration.
     
  4. Sep 6, 2005 #3
    Yep, that's the one.

    [itex]2\int_{0}^{1}\left(\sqrt{4x}\right)dx[/itex] (Is this the simplified form?)
     
    Last edited: Sep 6, 2005
  5. Sep 6, 2005 #4
    Alright, you can take the square root of 4. Now you have the following:

    [tex]4\int_0^1\sqrt{x}dx=\frac{8{\sqrt{x}}^3}{3}\right|_0^1=\boxed{\frac{8}{3}}[/tex]

    Yes, you simplified correctly.
     
    Last edited: Sep 7, 2005
  6. Sep 6, 2005 #5
    Ahh, I see what I did I think. I think I tried to just throw out the 1 and ended up with (8^(3/2))/3

    Thanks for the help!
    It's hard to stop from taking shortcuts! Argh! :redface:
     
    Last edited: Sep 6, 2005
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