# Integral hyperbolic cosine

From Encyclopedia of Mathematics

The special function defined, for real , by

where is the Euler constant and is the integral cosine. The integral hyperbolic cosine can be represented by the series

Sometimes it is denoted by .

For references, see Integral cosine.

#### Comments

This function, which is seldom used because of its relation with the cosine integral, is also called the hyperbolic cosine integral. It can, of course be defined (as above) for .

One has , where is the integral hyperbolic sine and is the integral logarithm.

**How to Cite This Entry:**

Integral hyperbolic cosine.

*Encyclopedia of Mathematics.*URL: http://encyclopediaofmath.org/index.php?title=Integral_hyperbolic_cosine&oldid=12550

This article was adapted from an original article by A.B. Ivanov (originator), which appeared in Encyclopedia of Mathematics - ISBN 1402006098. See original article