Section Scal_l.
Context {K : AbsRing} {V : NormedModule K}.
End Scal_l.

Lemma Derive_pow (f : R -> R) (n : nat) (x : R) :
ex_derive f x -> Derive (fun x => (f x)^n) x = (INR n * Derive f x * (f x)^(pred n)).