Hello all:

I seen a problem on another site where someone was wanting to know the inverse.

As Pka said, the derivative is always positive, so it has an inverse, but can not be found by elementary means.

I ran it through Maple and it kicked back:

What is Lambert?. I am unfamiliar. Does anyone know how this would be done without technology?. I thought it would something interesting to look into. I did find an interesting page on Wiki