# Separable polynomial with repeated roots.

Let $$E/F$$ be an extension and $$f \in F[X]$$. I was reading a statement saying if $$f$$ is separable and has multiple roots (repeated roots), these roots must be in $$F$$. I don't understand this. Isn't the fact that $$f$$ is separable supposed to mean that it has distinct roots? And why would they be in $$F$$?