On an Approximation by Band-Limited Functions

The problem of approximating a continuous real function of one real variable defined on an interval using a band-limited function based on Tikhonov’s regularization method is considered. Numerical estimates of the accuracy of such approximations are calculated for a model trigonometric function. We analyze why a theoretical estimate for the approximation accuracy of a continuous function by band-limited functions is difficult to achieve numerically. The problem of estimating the spectrum of a signal defined on a finite interval is discussed.