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Name

exp2, exp2f, exp2l - base-2 exponential function

Library

Math library ( libm ", " -lm )

Synopsis

#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

Description

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).

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).

Attributes

For an explanation of the terms used in this section, see attributes(7). allbox; lbx lb lb T{ exp2()exp2f()exp2l()
InterfaceAttributeValue
T}Thread safetyMT-Safe

Standards

C11, POSIX.1-2008.

History

glibc 2.1. C99, POSIX.1-2001.

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

See Also

  1. cbrt(3),
  2. cexp2(3),
  3. exp(3),
  4. exp10(3),
  5. sqrt(3)