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Homework Help: Integral help

  1. Feb 4, 2008 #1
    1. The problem statement, all variables and given/known data
    Not real good with the easy text stuff yet so ill give it a shot.

    definite integral of (1/(1+t^2))dt from 0 to x^2
    then find the interval for which the curve is concave upward.

    I totally forgot how to integrate problems like this. It is some sort of substitution I know.


    Would the integral of this involve a natural log?
    Last edited: Feb 4, 2008
  2. jcsd
  3. Feb 4, 2008 #2
    What you have in your integral is arctan. Probably something you should memorize.
  4. Feb 4, 2008 #3


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    You'd need a trigonometric substitution for that integral. It works out quite neatly in the end.

    Or recognise that the integrand is the derivative of arctan.
    Last edited: Feb 4, 2008
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