ACOSH(3) Library Functions Manual ACOSH(3)

acosh asinh atanhinverse hyperbolic functions

#include <math.h>

double acosh(double x);
double asinh(double x);
double atanh(double x);

The acosh() , asinh() and atanh() functions compute the inverse hyperbolic cosine, sine, and tangent of their argument, respectively.

The acosh() , asinh() and atanh() functions return the inverse hyperbolic cosine, sine, and tangent of their argument, respectively.

The acosh() function returns an implementation-dependent value (NaN or equivalent if available) and sets errno to [EDOM] when its argument is less than 1.0.

The atanh() function returns an implementation-dependent value (NaN or equivalent if available) and sets errno to [EDOM] when its argument has absolute value greater than 1.0.

If is NaN, the asinh(), acosh() and atanh() functions return NaN and may set errno to [EDOM].

The acosh() function will fail if:

The x argument is less than 1.0.

The atanh() function will fail if:

The x argument has an absolute value greater than 1.0.

The atanh() function will fail if:

The x argument has an absolute value equal to 1.0

The asinh(), acosh() and atanh() functions may fail if:

The value of x is NaN.

None.

None.

None.

cosh(3) , sinh(3) , tanh(3) , <math.h> .

February 1997 posix.fail