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 of arg (

tanh(arg)

, or

e arg -e -arg e arg +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 << 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

sinhsinhfsinhl (C++11)(C++11)	computes hyperbolic sine (${\small\sinh{x} }$ $sinh(x)$ ) (function)
coshcoshfcoshl (C++11)(C++11)	computes hyperbolic cosine (${\small\cosh{x} }$ $cosh(x)$ ) (function)
atanhatanhfatanhl (C++11)(C++11)(C++11)	computes the inverse hyperbolic tangent (${\small\operatorname{artanh}{x} }$ $artanh(x)$ ) (function)
tanh(std::complex)	computes hyperbolic tangent of a complex number (${\small\tanh{z} }$ $tanh(z)$ ) (function template)
tanh(std::valarray)	applies the function std::tanh to each element of valarray (function template)

Compiler support
Freestanding and hosted
Language
Standard library headers
Named requirements
Feature test macros (C++20)
Language support library
Concepts library (C++20)
Metaprogramming library (C++11)
Diagnostics library
General utilities library
Strings library
Containers library
Iterators library
Ranges library (C++20)
Algorithms library
Numerics library
Localizations library
Input/output library
Filesystem library (C++17)
Regular expressions library (C++11)
Concurrency support library (C++11)
Technical specifications
Symbols index
External libraries

Common mathematical functions
Mathematical special functions (C++17)
Mathematical constants (C++20)
Floating-point environment (C++11)
Complex numbers
Numeric arrays
Pseudo-random number generation
Factor operations
gcd (C++17)
lcm (C++17)
Interpolations
midpoint (C++20)
lerp (C++20)
Generic numeric operations
iota (C++11)
ranges::iota (C++23)
accumulate
inner_product
adjacent_difference
partial_sum
reduce (C++17)
transform_reduce (C++17)
inclusive_scan (C++17)
exclusive_scan (C++17)
transform_inclusive_scan (C++17)
transform_exclusive_scan (C++17)
Bit operations
bit_cast (C++20)
byteswap (C++23)
has_single_bit (C++20)
bit_ceil (C++20)
bit_floor (C++20)
bit_width (C++20)
rotl (C++20)
rotr (C++20)
countl_zero (C++20)
countl_one (C++20)
countr_zero (C++20)
countr_one (C++20)
popcount (C++20)
endian (C++20)