I'm taking a materials science class and we were introduced to the erf(z) function.(adsbygoogle = window.adsbygoogle || []).push({});

[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?

Thanks.

The article I was reading can be found http://en.wikipedia.org/wiki/Error_function" [Broken].

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Inverse of erf(z)?

Can you offer guidance or do you also need help?

**Physics Forums | Science Articles, Homework Help, Discussion**