English
For p, q ∈ R[X] and r ∈ R, r^{deg p + deg q − deg(p q)} · (p q).scaleRoots r = p.scaleRoots r · q.scaleRoots r.
Русский
Для p, q ∈ R[X] и r ∈ R верно: r^{deg p + deg q − deg(p q)} · (p q).scaleRoots r = p.scaleRoots r · q.scaleRoots r.
LaTeX
$$$ r^{\operatorname{natDegree}(p) + \operatorname{natDegree}(q) - \operatorname{natDegree}(p q)} \cdot (p q).\scaleRoots r = p.\scaleRoots r \cdot q.\scaleRoots r $$$
Lean4
@[simp]
theorem scaleRoots_mul (p : R[X]) (r s) : p.scaleRoots (r * s) = (p.scaleRoots r).scaleRoots s := by ext;
simp [mul_pow, mul_assoc]