Results 1 to 4 of 4

Math Help - Integration

  1. #1
    Super Member 11rdc11's Avatar
    Joined
    Jul 2007
    From
    New Orleans
    Posts
    894

    Integration

    I was searching videoes on laplace transfroms and came across this form of integration. My question is in what math class do they teach you this form of integration, complexifying the integral.

    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    Joined
    Jun 2009
    Posts
    806
    Thanks
    4
    You can do the integration of e^x*cosx or e^-x*cosx by using the integration by parts, where the original integration appears again. To avoid this, complexificaion method is used, which is easier than the other method. In place of cosx, if you have sinx , still you can use this method. Only difference is that in the final answer, you have to choose the imaginary part for the answer.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Banned
    Joined
    Oct 2009
    Posts
    4,261
    Thanks
    2
    Quote Originally Posted by 11rdc11 View Post
    I was searching videoes on laplace transfroms and came across this form of integration. My question is in what math class do they teach you this form of integration, complexifying the integral.


    I suppose it is in calculus I class: you only need to know the basics of integration and complex numbers. It's a nice trick, pretty standard among many teachers, but completely (and inexplicably so) unknown or unused among many others.

    Tonio
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Super Member 11rdc11's Avatar
    Joined
    Jul 2007
    From
    New Orleans
    Posts
    894
    Yes I did it by integration by parts but thought it was a lot easier with that little trick. I thought maybe in calc 2 where I was taught different techniques on how to integrate but none of my calc classes ever dealt with complex numbers.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 3
    Last Post: November 3rd 2010, 01:54 AM
  2. Replies: 2
    Last Post: November 2nd 2010, 05:57 AM
  3. Replies: 8
    Last Post: September 2nd 2010, 01:27 PM
  4. Replies: 2
    Last Post: February 19th 2010, 11:55 AM
  5. Replies: 6
    Last Post: May 25th 2009, 07:58 AM

Search Tags


/mathhelpforum @mathhelpforum