std::tanh, std::tanhf, std::tanhl
Defined in header <cmath> |
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|---|---|---|
| (1) | ||
float tanh ( float arg ); |
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float tanhf( float arg ); |
(since C++11) | |
double tanh ( double arg ); |
(2) | |
| (3) | ||
long double tanh ( long double arg ); |
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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) 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 << std::showpos
<< "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:
<< "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
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(C++11)(C++11)
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computes hyperbolic sine (\({\small\sinh{x} }\)sinh(x)) (function) |
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(C++11)(C++11)
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computes hyperbolic cosine (\({\small\cosh{x} }\)cosh(x)) (function) |
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(C++11)(C++11)(C++11)
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computes the inverse hyperbolic tangent (\({\small\operatorname{artanh}{x} }\)artanh(x)) (function) |
| computes hyperbolic tangent of a complex number (\({\small\tanh{z} }\)tanh(z)) (function template) |
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applies the function std::tanh to each element of valarray (function template) |
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C documentation for tanh |
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