exp() -- Mathematics Function (libm)

Compute exponent
#include <math.h>
double exp(z) double z;

exp() returns the exponential of z, or e^z.

Example

The following  example, called apr.c,  computes the annual  percentage rate
(APR) for a given rate of interest.  Compile it with the command:

    cc -f apr.c -lm

It is by Brent Seidel (brent_seidel@chthone.stat.com):

#include <math.h>
#include <stdio.h>
#include <stdlib.h>

main()
{
    double rate, APR;
    char buffer[50];

    printf("Enter interest rate in percent (e.g., 12.9): ");
    fflush(stdout);

    if (gets(buffer) == NULL)
        exit(EXIT_FAILURE);
    rate = strtod(buffer);

    APR = (exp(rate/100.0) - 1) * 100.0;
    printf("The APR for %g%% compounded daily is %g%%\n", rate, APR);
}

See Also

errno,
frexp(),
ldexp(),
libm
ANSI Standard, §7.5.4.1
POSIX Standard, §8.1

Diagnostics

exp() indicates overflow by an errno of ERANGE and a huge returned value.

© 2012 by Stephen A. Ness