acoshl Function

Calculates the arc hyperbolic cosine function of a double precision floating-point value.

Include

<math.h>

Prototype

long double acoshl(long double x);

Argument

x

value for which to return the arc hyperbolic cosine

Return Value

Returns the arc hyperbolic cosine of x.

Remarks

A range error will occur if the argument is less than 1.

Example

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

int main(void)
{
  long double x, y;

  errno = 0;
  x = 0.0;
  y = acoshl(x);
  if (errno)
    perror("Error");
  printf("The arc hyperbolic cosine of %Lf is %Lf\n", x, y);

  errno = 0;
  x = 1.0;
  y = acoshl(x);
  if (errno)
    perror("Error");
  printf("The arc hyperbolic cosine of %Lf is %Lf\n", x, y);

  errno = 0;
  x = 720.0;
  y = acoshl(x);
  if (errno)
    perror("Error");
  printf("The arc hyperbolic cosine of %Lf is %Lf\n", x, y);
}

Example Output

Error: range error
The arc hyperbolic cosine of 0.000000 is nan
The arc hyperbolic cosine of 1.000000 is 0.000000
The arc hyperbolic cosine of 720.000000 is 7.272398