English
For any natural k, the kth iterate of the derivative commutes with scalar multiplication: derivative^[k](s · p) = s · derivative^[k] p.
Русский
Для любого натурального k кратная итерация производной коммутирует со скаляром: D^k(s · p) = s · D^k(p).
LaTeX
$$$\operatorname{derivative}^{k}(s \cdot p) = s \cdot \operatorname{derivative}^{k}(p)$$$
Lean4
@[simp]
theorem iterate_derivative_smul {S : Type*} [SMulZeroClass S R] [IsScalarTower S R R] (s : S) (p : R[X]) (k : ℕ) :
derivative^[k] (s • p) = s • derivative^[k] p := by
induction k generalizing p with
| zero => simp
| succ k ih => simp [ih]