tanh, tanhf, tanhl − hyperbolic tangent function
float tanhf(float x);
long double tanhl(long double x);
Link with −lm.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
_BSD_SOURCE || _SVID_SOURCE ||
_XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
or cc -std=c99
These functions return the hyperbolic tangent of x, which is defined mathematically as:
tanh(x) = sinh(x) / cosh(x)
On success, these functions return the hyperbolic tangent of x.
If x is a NaN, a NaN is returned.
If x is +0 (−0), +0 (−0) is returned.
If x is positive infinity (negative infinity), +1 (−1) is returned.
No errors occur.
For an explanation of the terms used in this section, see attributes(7).
C99, POSIX.1-2001, POSIX.1-2008.
The variant returning double also conforms to SVr4, 4.3BSD, C89.
acosh(3), asinh(3), atanh(3), cosh(3), ctanh(3), sinh(3)
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