1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Definite integral with x^2+c in the denominator

  1. Jan 30, 2014 #1
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    solve the definite integral

    [tex]\int_{2.6}^{5.5} \frac{1}{x^2+9}dx[/tex]

    3. The attempt at a solution

    ln(5.5^2+9)-ln(2.6^2+9) doesn't seem correct
  2. jcsd
  3. Jan 30, 2014 #2

    king vitamin

    User Avatar
    Gold Member

    Can you show your steps in getting that solution? What did you get for the antiderivative of the integrand?
  4. Jan 30, 2014 #3


    User Avatar
    Science Advisor
    Homework Helper

    If you take the derivative of log(x^2+9) you will not get 1/(x^2+9) (at least if you don't forget the chain rule). You need a trig substitution to do that integral.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted