Results 1 to 3 of 3

Math Help - 2nd order linear differential equation

  1. #1
    Junior Member
    Joined
    Sep 2010
    From
    Oslo
    Posts
    57
    Thanks
    4

    2nd order linear differential equation

    Hi, can anyone tell me why this is wrong?

    First I factor the characteristic equation and get that r is either 0 or -1:
    2nd order linear differential equation-picture-5.png

    Then I plug those values into the solution for two real roots:

    2nd order linear differential equation-picture-8.png

    But according to wolfram the second term is supposed to be negative. Why is that?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member Random Variable's Avatar
    Joined
    May 2009
    Posts
    959
    Thanks
    3
    Because Wolfram Alpha is stupid? Since  C_{2} can be positive or negative, it can absorb the negative.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Sep 2010
    From
    Oslo
    Posts
    57
    Thanks
    4
    Haha! That makes sense. Thanks
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. First Order Linear Differential Equation
    Posted in the Differential Equations Forum
    Replies: 4
    Last Post: March 11th 2011, 04:38 AM
  2. First Order Non-Linear Differential Equation
    Posted in the Differential Equations Forum
    Replies: 2
    Last Post: October 3rd 2010, 10:46 AM
  3. First Order Linear Differential Equation
    Posted in the Differential Equations Forum
    Replies: 3
    Last Post: August 11th 2010, 03:15 AM
  4. First-Order Linear Differential Equation
    Posted in the Differential Equations Forum
    Replies: 2
    Last Post: May 1st 2010, 10:58 AM
  5. Second order non linear differential equation.
    Posted in the Differential Equations Forum
    Replies: 0
    Last Post: February 20th 2010, 12:49 PM

Search Tags


/mathhelpforum @mathhelpforum