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Inverse of erf(z)?

  1. Feb 11, 2009 #1
    I'm taking a materials science class and we were introduced to the erf(z) function.

    [tex]erf(z) = 2/sqrt(\pi) \int^{z}_0 {e^{-y^2}[/tex]

    Because the calculus required to calculate this is very lengthy, he pointed us to a table to look up the values. Instead, I programmed the function into my calculator to quickly find values for erf(z).

    However, sometimes we need to find the value for z for a given value of erf(z). I'm having trouble solving explicitly for z, but it seems like there should be a good way to find the inverse of the function. I did some searching on Wikipedia, but I didn't understand the taylor series representation of the inverse; it included [tex]C_m[/tex] and [tex]C_k[/tex]. I wasn't sure what to do with these. Can someone please explain it or tell me how to program an inverse of this function into my calculator?


    The article I was reading can be found http://en.wikipedia.org/wiki/Error_function" [Broken].
    Last edited by a moderator: May 4, 2017
  2. jcsd
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