**NAME**

exp2, exp2f, exp2l - base-2 exponential function

**SYNOPSIS**

**#include** **<math.h>**
**double** **exp2(double** __x__**);**
**float** **exp2f(float** __x__**);**
**long** **double** **exp2l(long** **double** __x__**);**
Link with __-lm__.
Feature Test Macro Requirements for glibc (see **feature_test_macros**(7)):
**exp2**(), **exp2f**(), **exp2l**(): _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or
__cc__ __-std=c99__

**DESCRIPTION**

The **exp2**() function returns the value of 2 raised to the power of __x__.

**RETURN** **VALUE**

On success, these functions return the base-2 exponential value of __x__.
For various special cases, including the handling of infinity and NaN,
as well as overflows and underflows, see **exp**(3).

**ERRORS**

See **math_error**(7) for information on how to determine whether an error
has occurred when calling these functions.
For a discussion of the errors that can occur for these functions, see
**exp**(3).

**VERSIONS**

These functions first appeared in glibc in version 2.1.

**CONFORMING** **TO**

C99, POSIX.1-2001. The variant returning __double__ also conforms to SVr4,
4.3BSD, C89.

**SEE ALSO**

**cbrt**(3), **cexp2**(3), **exp**(3), **exp10**(3), **sqrt**(3)

**COLOPHON**

This page is part of release 3.24 of the Linux __man-pages__ project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
2008-08-11