English
The derivative of x^p (1D) is p x^{p-1} when the condition holds.
Русский
Производная x^p (одномерная) равна p x^{p-1} при условии.
LaTeX
$$$\\text{deriv }(x^p)=p x^{p-1}\\quad\\text{ under conditions.}$$$
Lean4
@[fun_prop]
theorem rpow (hf : DifferentiableWithinAt ℝ f s x) (hg : DifferentiableWithinAt ℝ g s x) (h : f x ≠ 0) :
DifferentiableWithinAt ℝ (fun x => f x ^ g x) s x := by
-- `by exact` to deal with tricky unification.
exact (differentiableAt_rpow_of_ne (f x, g x) h).comp_differentiableWithinAt x (hf.prodMk hg)