std::tanh, std::tanhf, std::tanhl
| Defined in header <cmath> | ||
|---|---|---|
| (1) | ||
| float tanh ( float arg ); | ||
| float tanhf( float arg ); | (since C++11) | |
| double tanh ( double arg ); | (2) | |
| (3) | ||
| long double tanh ( long double arg ); | ||
| long double tanhl( long double arg ); | (since C++11) | |
| double tanh ( IntegralType arg ); | (4) | (since C++11) | 
1-3) Computes the hyperbolic tangent of 
 arg
4) A set of overloads or a function template accepting an argument of any integral type. Equivalent to 2) (the argument is cast to 
 double).Parameters
| arg | - | value of a floating-point or Integral type | 
Return value
If no errors occur, the hyperbolic tangent ofarg (tanh(arg), or | earg -e-arg | 
| earg +e-arg | 
If a range error occurs due to underflow, the correct result (after rounding) is returned.
Error handling
Errors are reported as specified in math_errhandling.
If the implementation supports IEEE floating-point arithmetic (IEC 60559),
- if the argument is ±0, ±0 is returned
- If the argument is ±∞, ±1 is returned
- if the argument is NaN, NaN is returned
Notes
POSIX specifies that in case of underflow, arg is returned unmodified, and if that is not supported, and implementation-defined value no greater than DBL_MIN, FLT_MIN, and LDBL_MIN is returned.
Examples
#include <iostream>
#include <cmath>
 
int main()
{
    std::cout << "tanh(1) = " << std::tanh(1) << '\n'
              << "tanh(-1) = " << std::tanh(-1) << '\n'
              << "tanh(0.1)*sinh(0.2)-cosh(0.2) = "
              << std::tanh(0.1) * std::sinh(0.2) - std::cosh(0.2) << '\n';
    // special values
    std::cout << "tanh(+0) = " << std::tanh(+0.0) << '\n'
              << "tanh(-0) = " <<  std::tanh(-0.0) << '\n';
}Output:
tanh(1) = 0.761594 tanh(-1) = -0.761594 tanh(0.1)*sinh(0.2)-cosh(0.2) = -1 tanh(+0) = 0 tanh(-0) = -0
See also
| (C++11)(C++11) | computes hyperbolic sine (sh(x)) (function) | 
| (C++11)(C++11) | computes hyperbolic cosine (ch(x)) (function) | 
| (C++11)(C++11)(C++11) | computes the inverse hyperbolic tangent (artanh(x)) (function) | 
| computes hyperbolic tangent of a complex number (function template) | |
| applies the function std::tanhto each element of valarray(function template) | 
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