1ATANH(3) Linux Programmer's Manual ATANH(3)
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6 atanh, atanhf, atanhl - inverse hyperbolic tangent function
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9 #include <math.h>
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11 double atanh(double x);
12 float atanhf(float x);
13 long double atanhl(long double x);
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15 Link with -lm.
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18 The atanh() function calculates the inverse hyperbolic tangent of x;
19 that is the value whose hyperbolic tangent is x. If the absolute value
20 of x is greater than 1.0, atanh() returns not-a-number (NaN) and errno
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24 EDOM x is out of range.
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27 SVr4, POSIX.1-2001, 4.3BSD, C89. The float and long double variants
28 are C99 requirements.
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31 acosh(3), asinh(3), catanh(3), cosh(3), sinh(3), tanh(3)
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35 2002-07-27 ATANH(3)