On degree of approximation of non-periodic function by Voronoi means of its Fourier integral

The theorem on the degree of approximation to a function $f(x) \in L(-\infty; \infty)$ by Voronoi means of its Fourier integral, as well as a theorem on the degree of approximation to a function $g(x) = \frac{1}{\pi} \int\limits_0^{\infty} \frac{f(x+t) - f(x-t)}{t} dt$ by the Voronoi means of its conjugate Fourier integral of a function $f(x)$, is proved.