EXP(3) | Library Functions Manual | EXP(3)

# NAME

`exp`, `expf`, `exp2`, `exp2f`, `expm1`, `expm1f` —
exponential functions

# LIBRARY

Math Library (libm, -lm)

# SYNOPSIS

`#include <math.h>`

double
`exp`(double x);

float
`expf`(float x);

double
`exp2`(double x);

float
`exp2f`(float x);

double
`expm1`(double x);

float
`expm1f`(float x);

# DESCRIPTION

The `exp`() and `expf`() functions compute the base e exponential value of the given argument x.

The `exp2`() and `exp2f`() functions compute the base 2 exponential of the given argument x.

The `expm1`() and `expm1f`() functions compute the value exp(x)-1 accurately even for tiny argument x.

# RETURN VALUES

These functions will return the appropriate computation unless an error occurs or an argument is out of range. The functions `exp`() and `expm1`() detect if the computed value will overflow, set the global variable errno to `ERANGE` and cause a reserved operand fault on a VAX.

# SEE ALSO

math(3)

# STANDARDS

The `exp`() function conforms to ANSI X3.159-1989 (“ANSI C89”). The `exp2`(), `exp2f`(), `expf`(), `expm1`(), and `expm1f`() functions conform to ISO/IEC 9899:1999 (“ISO C99”).

# HISTORY

The `exp`() functions appeared in Version 1 AT&T UNIX. The `expm1`() function appeared in 4.3BSD.

September 2, 2019 | NetBSD 9.2