exp(), expf(), expl() — Calculate exponential function
Standards
Standards / Extensions | C or C++ | Dependencies |
---|---|---|
ISO C |
both |
Format
#include <math.h>
double exp(double x);
float exp(float x); /* C++ only */
long double exp(long double x); /* C++ only */
float expf(float x);
long double expl(long double x);
General description
Calculates the exponent
of x, defined as e**x,
where e equals 2.17128128….
Note: These
functions work in both IEEE Binary Floating-Point and hexadecimal
floating-point formats. See IEEE binary floating-point for
more information about IEEE Binary Floating-Point.
Returned value
If successful, the function returns the calculated value.
If an overflow occurs, the function returns HUGE_VAL. If an underflow occurs, it returns 0. Both overflow and underflow set errno to ERANGE.
Example
CELEBE06
/* CELEBE06
This example calculates y as the exponential function of x.
*/
#include <math.h>
#include <stdio.h>
int main(void)
{
double x, y;
x = 5.0;
y = exp(x);
printf("exp( %f ) = %f\n", x, y);
}
Output
exp( 5.000000 ) = 148.413159