Facebook Page Twitter Page LinkedIn Page
× C Tutorial C Resources


The C math expm1() function is used to return e raised to the power of specified number minus 1, i.e., ex-1. Please note that e is the base of the natural system of logarithms, and its value is approximately 2.718282.

Syntax

double expm1(double x);
float expm1f(float x);
long double expm1l(long double x);

Parameters

x Specify the exponent of e.

Return Value

Returns e raised to the power of specified number minus 1, i.e., ex-1.

Example:

In the below example, expm1() function is used to calculate e raised to the power of specified number minus one.

#include <stdio.h>
#include <math.h>
 
int main (){
  printf("%lf\n", expm1(2));
  printf("%lf\n", expm1(-2));
  printf("%lf\n", expm1(1.5));
  printf("%lf\n", expm1(-1.5));  
  return 0;
}

The output of the above code will be:

6.389056
-0.864665
3.481689
-0.776870

❮ C <math.h> Library