English
Let A be an n×n matrix over a commutative ring. For every natural number k, the adjugate of A raised to the k-th power equals the k-th power of the adjugate of A: adj(A^k) = (adj A)^k.
Русский
Пусть A — квадратная матрица размерности n над коммутативным кольцом. Для любого натурального k выполняется adj(A^k) = (adj A)^k.
LaTeX
$$$\\operatorname{adj}(A^k) = \\operatorname{adj}(A)^k$$$
Lean4
@[simp]
theorem adjugate_pow (A : Matrix n n α) (k : ℕ) : adjugate (A ^ k) = adjugate A ^ k := by
induction k with
| zero => simp
| succ k IH => rw [pow_succ', adjugate_mul_distrib, IH, pow_succ]