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Homework Help: Summation math help

  1. Dec 6, 2008 #1
    Find an N so that
    N​
    0< e-[tex]\sum[/tex] 1/n! < 10^-14
    n=0​

    I seriously don't know how to go about this problem.
    Please help me out.

    Thanks
     
  2. jcsd
  3. Dec 6, 2008 #2

    lurflurf

    User Avatar
    Homework Helper

    Re: summation

    since we know
    e=1+1+1/2+1/6+...+1/n!+...
    e-(1+1+1/2+1/6+...+1/n!)=1/(n+1)!+...<1/(n*n!)
    so chose n at least so large that
    1/(n*n!)<10^-14
     
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