специальные ряды

Discrete Transform with Stick Property Based on {sinx sinkx} and Second Kind Chebyshev Polynomials Systems

In this paper we introduce the discrete series with the «sticking»-property of the periodic ({sinx sinkx} system) and non-periodic (using the system of the second kind of Chebyshev polynomials Uk(x)) cases. It is shown that series of the system {sinx sinkx}
have an advantage over cosine Fourier series because they have better approximation properties near the bounds of the [0, π] segment. Similarly discrete series of the system Uk(x) near the bound of the [−1, 1] approximates given function significantly