Abstract:
In this article we shall concern ourselves with determining exact (least possible) constants in the inequalities of the form $\|f^{(k)}\|_{L_q}\le K\|f\|_{L_p}^{\frac{l-k-r^{-1}+q^{-1}}{l-r^{-1}+p^{-1}}}\|f^{(l)}\|_{L_r}^{\frac{k-q^{-1}+p^{-1}}{l-r^{-1}+p^{-1}}}$ for functions defined on the entire $(-\infty,\infty)$, absolutely continuous on any interval together with their $(l-1)$-th derivatives, and having finite
$$
l=2,\quad k=0,\quad k=1,\quad q=r=\infty,\quad 1\leqslant p<\infty
$$
is considered.