std::tanh,std::tanhf,std::tanhl (3) - Linux Manuals

std::tanh,std::tanhf,std::tanhl: std::tanh,std::tanhf,std::tanhl

NAME

std::tanh,std::tanhf,std::tanhl - std::tanh,std::tanhf,std::tanhl

Synopsis

Defined in header <cmath>
float tanh ( float arg );
float tanhf( float arg ); (since C++11)
double tanh ( double arg ); (1) (2)
long double tanh ( long double arg );
long double tanhl( long double arg ); (3) (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 of arg (tanh(arg), or

earg
-e-arg
earg
+e-arg

) is returned.
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

// Run this code

  #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