Solution
= Solution
\b[True.] Repeated use of the <Leibniz rule> and the polynomial Taylor formula gives
$$
\boxed{P(D)(fg)=\sum_\alpha\frac1{\alpha!}
(D^\alpha f)\,P^{(\alpha)}(D)g.}
$$
= Solution
\b[True.] Repeated use of the <Leibniz rule> and the polynomial Taylor formula gives
$$
\boxed{P(D)(fg)=\sum_\alpha\frac1{\alpha!}
(D^\alpha f)\,P^{(\alpha)}(D)g.}
$$