# Math Help - What is the inverse function of f?

1. ## What is the inverse function of f?

What is the inverse function of f(x)=?

Thanks.

2. Actually, that has a very simple answer. The inverse function to $f(x)= xe^x$ is, by definition, $f^{-1}(x)= W(x)$, "Lambert's W function". It cannot be written in terms of elementary functions.

See http://en.wikipedia.org/wiki/Lambert's_W_function