std::tanh

float       tanh( float arg );

double      tanh( double arg );

long double tanh( long double arg );

double      tanh( Integral arg );

Computes the hyperbolic tangent of arg.

Parameters

Return value

If no errors occur, the hyperbolic tangent of arg (tanh(arg), or

) 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

#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';
}

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