EXP2(3) Linux Programmer's Manual EXP2(3)

exp2, exp2f, exp2l - base-2 exponential function

#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():

These functions return the value of 2 raised to the power of x.

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).

These functions first appeared in glibc in version 2.1.

For an explanation of the terms used in this section, see attributes(7).
Interface Attribute Value
exp2 (), exp2f (), exp2l () Thread safety MT-Safe

C99, POSIX.1-2001, POSIX.1-2008.
The variant returning double also conforms to SVr4, 4.3BSD.

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