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Math Help - Help!!!! Integration!!

  1. #1
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    Help!!!! Integration!!

    Hi! I am integrating (1) over (x^2+4x-32) and I know that that can be separated into the integral of (A) over (x-4) plus the integral of (B) over (x+8) but I don't know how to solve for A and B. I have 1= A(x+8) + B(x-4). So 1=Ax+A8+Bx+-B4. All I know is that (A+B)x, A+B=0 since there are no x variables. Just 1. Please help me figure out the values for A and B!!! It's probably easy I just am not figuring it out! Thanks!!
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  2. #2
    Super Member flyingsquirrel's Avatar
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    Hello
    Quote Originally Posted by elocin View Post
    Hi! I am integrating (1) over (x^2+4x-32) and I know that that can be separated into the integral of (A) over (x-4) plus the integral of (B) over (x+8) but I don't know how to solve for A and B. I have 1= A(x+8) + B(x-4). So 1=Ax+A8+Bx+-B4. All I know is that (A+B)x, A+B=0 since there are no x variables. Just 1. Please help me figure out the values for A and B!!!
    You're right, there is no x at the numerator so A+B=0. What you forgot is that the numerator of \frac{1}{x^2+4x-32} is 1 () so we also have 8A-4B=1.
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  3. #3
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    Hmm. Yes I think I knew that, but how do you solve for that? A and B have to be equal but opposite signs, so I don't know how to solve for it. I tried plugging in numbers, but I'm not getting anywhere!
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  4. #4
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    Never mind, it's 1/12!! Thanks!
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