Title pretty much said it. Maybe I'm just being a complete fool and its obvious.

For the precise problem:

Find stationary points: f(x) = (x^3)/3 + e^(-x)

f ' (x) = 0 = x^2 - e^(-x)

e^(-x) = x^2

I could use a numerical method (eg iteration), but surely theres a way to get the answer algebraically?

Thanks