acosh
calculates the inverse hyperbolic cosine
of x.
acosh
is defined as:
x must be a number greater than or equal to 1.
acoshf is identical, other than taking and returning floats.
acosh,
acoshf
[inverse hyperbolic
cosine]
SYNOPSIS
#include <math.h> double acosh(double x); float acoshf(float x);
DESCRIPTION
acosh
calculates the inverse hyperbolic cosine
of x.
acosh
is defined as:
x must be a number greater than or equal to 1.
acoshf is identical, other than taking and returning floats.
RETURN
acosh
and acoshf
return the calculated value. If x
less than 1, the return value is NaN
and errno
is set to EDOM.
You can change the error-handling behavior with the non-ANSI matherr function.
COMPLIANCE
Neither acosh
nor acoshf
are ANSI C.
They are not recommended for portable programs.