Results 1 to 4 of 4

Math Help - subtraction of series

  1. #1
    Junior Member
    Joined
    Mar 2009
    From
    Kentucky
    Posts
    72

    subtraction of series

    I know you can multiple series but if you want to find the series for e^x -\cos x can you subtract two known series.

    Is this valid \frac {e^x -\cos x}{x} = \sum \frac {x^{n-1}}{n!}-\frac{(-1)^nx^{2n-1}}{(2n)!}
    Last edited by manyarrows; April 26th 2009 at 05:28 PM. Reason: more info
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,831
    Thanks
    1602
    Quote Originally Posted by manyarrows View Post
    I know you can multiple series but if you want to find the series for e^x -\cos x can you subtract two known series.

    Is this valid \frac {e^x -\cos x}{x} = \sum \frac {x^{n-1}}{n!}-\frac{(-1)^nx^{2n-1}}{(2n)!}
    Yes it's valid.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member woof's Avatar
    Joined
    Apr 2009
    Posts
    31
    They probably want you to simplify it?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Jester's Avatar
    Joined
    Dec 2008
    From
    Conway AR
    Posts
    2,392
    Thanks
    56
    The reason why its valid is that both series converge for all x.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 2
    Last Post: December 1st 2009, 01:45 PM
  2. subtraction series from each other
    Posted in the Differential Geometry Forum
    Replies: 2
    Last Post: April 22nd 2009, 01:23 PM
  3. subtraction
    Posted in the Algebra Forum
    Replies: 3
    Last Post: May 9th 2008, 11:05 AM
  4. subtraction
    Posted in the Algebra Forum
    Replies: 3
    Last Post: May 9th 2008, 09:58 AM
  5. subtraction
    Posted in the Algebra Forum
    Replies: 1
    Last Post: May 9th 2008, 08:33 AM

Search Tags


/mathhelpforum @mathhelpforum