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exp2 - Man Page

base-2 exponential function


Math library (libm, -lm)


#include <math.h>

double exp2(double x);
float exp2f(float x);
long double exp2l(long double x);

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

exp2(), exp2f(), exp2l():

    _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L


These functions return 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).


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).


For an explanation of the terms used in this section, see attributes(7).

exp2(), exp2f(), exp2l()Thread safetyMT-Safe


C11, POSIX.1-2008.


glibc 2.1. C99, POSIX.1-2001.

The variant returning double also conforms to SVr4, 4.3BSD.

See Also

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

Referenced By

exp(3), exp10(3).

The man pages exp2f(3) and exp2l(3) are aliases of exp2(3).

2024-05-02 Linux man-pages 6.8