7.12.6.3 The expm1 functions

Synopsis

1

#include <math.h>
double expm1(double x);
float expm1f(float x);
long double expm1l(long double x);

Description

2

The expm1 functions compute the base-e exponential of the argument, minus 1. A range error occurs if x is too large.[1]

Returns

3

The expm1 functions return e^x - 1.

Footnotes

[1]

For small magnitude x, expm1(x) is expected to be more accurate than exp(x) - 1.