# Trigonometric polynomial

From Encyclopedia of Mathematics

*finite trigonometric sum*

An expression of the form

with real coefficients , ; the number is called the order of the trigonometric polynomial (provided ). A trigonometric polynomial can be written in complex form:

where

Trigonometric polynomials are an important tool in the approximation of functions.

#### Comments

Cf. also Trigonometric series.

**How to Cite This Entry:**

Trigonometric polynomial.

*Encyclopedia of Mathematics.*URL: http://encyclopediaofmath.org/index.php?title=Trigonometric_polynomial&oldid=11930

This article was adapted from an original article by V.I. Bityutskov (originator), which appeared in Encyclopedia of Mathematics - ISBN 1402006098. See original article