NAME    [Toc]    [Back]

     atanh, atanhf - inverse hyperbolic tangent function

LIBRARY    [Toc]    [Back]

     Math Library (libm, -lm)

SYNOPSIS    [Toc]    [Back]

     #include <math.h>

     double
     atanh(double x);

     float
     atanhf(float x);

DESCRIPTION    [Toc]    [Back]

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

RETURN VALUES    [Toc]    [Back]

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

SEE ALSO    [Toc]    [Back]

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

HISTORY    [Toc]    [Back]

     The atanh() function appeared in 4.3BSD.

BSD                               May 6, 1991                              BSD