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: Solving Integrals Using a Known Mac Series (Sin(x))

  1. Feb 24, 2009 #1
    1. The problem statement, all variables and given/known data
    Assume that sin(x) equals its Maclaurin series for all x. Use the Maclaurin series for sin(7x^2) to evaluate the integral https://webwork.math.lsu.edu/webwork2_files/tmp/equations/f4/767c0643696d085d77f9a697294a311.png

    Your answer will be an infinite series. Use the first two terms to estimate its value.

    2. Relevant equations

    3. The attempt at a solution
    http://img27.imageshack.us/img27/5028/mathhelp2k.jpg [Broken]

    After the final step in the picture, I plugged in n=0 and 1 to get my 0th and 1st terms, then I added them together and I got: 0.754110411. This is wrong, however.. can someone please help me diagnose this problem?
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Feb 24, 2009 #2
    You forgot powering the 7, you need 7^(2n+1).
  4. Feb 24, 2009 #3
    Thank you, I see my error now and the suggestion lead me to a correct answer.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook