tanh - hyperbolic tangent function
#include <math.h> double tanh(double x);
The tanh() function computes the hyperbolic tangent of x.
An application wishing to check for error situations should set errno to 0 before calling tanh(). If errno is non-zero on return, or the return value is NaN, an error has occurred.
Upon successful completion, tanh() returns the hyperbolic tangent of x.
If x is NaN, NaN is returned and errno may be set to [EDOM].
If the correct value would cause underflow, 0.0 is returned and errno may be set to [ERANGE].
The tanh() function may fail if:
- The value of x is NaN.
- The correct result would cause underflow.
No other errors will occur.
atanh(), isnan(), tan(), <math.h>.
Derived from Issue 1 of the SVID.