ATANH(3) Library Functions Manual ATANH(3)

atanh, atanhf, atanhl
inverse hyperbolic tangent function

Math Library (libm, -lm)

#include <math.h>

double
atanh(double x);

float
atanhf(float x);

long double
atanhl(long double x);

The atanh(), atanhf(), and atanhl() functions compute the inverse hyperbolic tangent of the real argument x.

If |x|≥1, atanh(x), atanhf(x), and atanhl(x) return +inf, -inf or NaN, and sets the global variable errno to EDOM.

acosh(3), asinh(3), exp(3), math(3)

The atanh() function conforms to ISO/IEC 9899:1999 (“ISO C99”).

The atanh() function appeared in 4.3BSD.
January 29, 2013 NetBSD 9.0