acoshf (3) manual page

Table of Contents

Name

acosh, acoshf, acoshl - inverse hyperbolic cosine function

Synopsis

#include <math.h>

double acosh(double x);
float acoshf(float x);
long double acoshl(long double x);

Link with -lm.

Description

The acosh() function calculates the inverse hyperbolic cosine of x; that is the value whose hyperbolic cosine is x. If x is less than 1.0, acosh() returns not-a-number (NaN) and errno is set.

Errors

EDOM
x is out of range.

Conforming to

SVr4, POSIX.1-2001, 4.3BSD, C89. The float and long double variants are C99 requirements.

See Also

asinh(3) , atanh(3) , cacosh(3) , cosh(3) , sinh(3) , tanh(3)


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