Let $f$ be a function such that :$f:\mathbb{R}\to \mathbb{R}$ and $f^{-1}$ is a compositional inverse of $f$. I would'd like to know how do I solve this class of differential equation : $$\displaystyle \ f'= e^{\displaystyle {f}^{-1}}$$ ?. **Note 01:** $f' =\displaystyle\frac{df}{dx}$. **Edit:** ${f}^{-1}$ is the inverse compositional of $f$, for example $\log$ is the inverse application of exp function . **Note 02**: I have edited my question to clarify the titled question that related to ${f}^{-1}$ Thank you for any help