From cppreference.com
Defined in header
floattanh(floatnum);doubletanh(doublenum);longdoubletanh(longdoublenum); (1)(until C++23)/*floating-point-type*/tanh(/*floating-point-type*/num);(since C++23)
(constexpr since C++26)floattanhf(floatnum); (2)(since C++11)
(constexpr since C++26)longdoubletanhl(longdoublenum); (3)(since C++11)
(constexpr since C++26)
(since C++26)
Defined in header
template</*math-floating-point*/V>constexpr/*deduced-simd-t*/<V>tanh(constV&v_num); (S) (since C++26)
(since C++11)
Defined in header
template<classInteger>doubletanh(Integernum); (A)(constexpr since C++26)1-3) Computes the hyperbolic tangent of num. The library provides overloads of std::tanh for all cv-unqualified floating-point types as the type of the parameter.(since C++23)
A) Additional overloads are provided for all integer types, which are treated as double.
(since C++11)Parameters
num - floating-point or integer value Return value
If no errors occur, the hyperbolic tangent of num (tanh(num), or
enum
-e-num
enum
+e-num
) 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
.
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
that in case of underflow, num 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.
The additional overloads are not required to be provided exactly as (A). They only need to be sufficient to ensure that for their argument num of integer type, std::tanh(num) has the same effect as std::tanh(static_cast<double>(num)).
Example
Run this code
#include<cmath>#include<iostream>#include<random>doubleget_random_between(doublemin,doublemax){std::random_devicerd;std::mt19937gen(rd());returnstd::uniform_real_distribution<>(min,max)(gen);}intmain(){constdoublex=get_random_between(-1.0,1.0);std::cout<<std::showpos<<"tanh(+1) = "<<std::tanh(+1)<<'\n'<<"tanh(-1) = "<<std::tanh(-1)<<'\n'<<"tanh(x)*sinh(2*x)-cosh(2*x) = "<<std::tanh(x)*std::sinh(2*x)-std::cosh(2*x)<<'\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(x)*sinh(2*x)-cosh(2*x) = -1 tanh(+0) = +0 tanh(-0) = -0 See also
(C++11)(C++11)
computes hyperbolic sine (sinh(x))
(function)
(C++11)(C++11)
computes hyperbolic cosine (cosh(x))
(function)
(C++11)(C++11)(C++11)
computes the inverse hyperbolic tangent (artanh(x))
(function)
computes hyperbolic tangent of a complex number (tanh(z))
(function template)
applies the function
to each element of valarray
(function template)
for tanh