Let $f \in C^{\infty}(A)$, $A \subset \mathbb{R}$ compact. Is it true that $|| f^{(k)} ||_p < \infty$, for each naturals pair $p,k$?
My attempt. Since $A$ is compact and $f \in C^{\infty}(A)$ then for each $k$ natural $f^{(k)}(A)$ is compact as well, and it is bounded specifically. So is it is $|f^{(k)}|$, and same as $|f^{(k)}|^p$, so for each pair $(k,p)$ the function $g(x;p,k) = |f^{(k)}(x)|^p$ is Reinmann integrable, and therefore is Lebesgue integrable. And the integral
$$I_{p,k} = \int_{A} g(x;p,k) dx$$
Since $I_{p,k} = ||f^{(k)}||_p$ this completes the proof.
Assuming is correct, can the argument be generalized for any measure $\mu$? If not where's my mistake?
(I'm a little bit rusty in these things).
Since $f^{(k)}$ is bounded, i.e. $|f^k(x)|\leq M_k $, for any finite measure $\mu$ on $A$, i.e. with $\mu(A)<\infty$, you have $$ \int|f^{(k)}(x)|^pd\mu\leq M^p_k\mu(A)<\infty, $$ i.e. $f^{(k)}\in L^p(A,d\mu)$.