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'\" t
.\" Copyright, the authors of the Linux man-pages project
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.TH exp2 3 2025-05-17 "Linux man-pages (unreleased)"
.SH NAME
exp2, exp2f, exp2l \- base-2 exponential function
.SH LIBRARY
Math library
.RI ( libm ,\~ \-lm )
.SH SYNOPSIS
.nf
.B #include <math.h>
.P
.BI "double exp2(double " x );
.BI "float exp2f(float " x );
.BI "long double exp2l(long double " x );
.fi
.P
.RS -4
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.RE
.P
.BR exp2 (),
.BR exp2f (),
.BR exp2l ():
.nf
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
.fi
.SH DESCRIPTION
These functions return the value of 2 raised to the power of
.IR x .
.SH RETURN VALUE
On success, these functions return the base-2 exponential value of
.IR x .
.P
For various special cases, including the handling of infinity and NaN,
as well as overflows and underflows, see
.BR exp (3).
.SH ERRORS
See
.BR math_error (7)
for information on how to determine whether an error has occurred
when calling these functions.
.P
For a discussion of the errors that can occur for these functions, see
.BR exp (3).
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lbx lb lb
l l l.
Interface Attribute Value
T{
.na
.nh
.BR exp2 (),
.BR exp2f (),
.BR exp2l ()
T} Thread safety MT-Safe
.TE
.SH STANDARDS
C11, POSIX.1-2008.
.SH HISTORY
glibc 2.1.
C99, POSIX.1-2001.
.P
The variant returning
.I double
also conforms to
SVr4, 4.3BSD.
.SH SEE ALSO
.BR cbrt (3),
.BR cexp2 (3),
.BR exp (3),
.BR exp10 (3),
.BR sqrt (3)
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