std::cosh, std::coshf, std::coshl

Defined in header `<cmath>`
	(1)
float cosh ( float arg );
float coshf( float arg );			(since C++11)
double cosh ( double arg );		(2)
		(3)
long double cosh ( long double arg );
long double coshl( long double arg );				(since C++11)
double cosh ( IntegralType arg );			(4)	(since C++11)

1-3) Computes the hyperbolic cosine 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 cosine of arg (

cosh(arg)

, or

e arg +e -arg 2

) is returned.

If a range error due to overflow occurs, +HUGE_VAL, +HUGE_VALF, or +HUGE_VALL 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, 1 is returned
If the argument is ±∞, +∞ is returned
if the argument is NaN, NaN is returned

Notes

For the IEEE-compatible type double, if $|arg| > 710.5$ , then cosh(arg) overflows.

Example

Run this code

#include <iostream>
#include <cmath>
#include <cerrno>
#include <cstring>
#include <cfenv>
 
// #pragma STDC FENV_ACCESS ON
int main()
{
    std::cout << "cosh(1) = " << std::cosh(1) << '\n'
              << "cosh(-1) = " << std::cosh(-1) << '\n'
              << "log(sinh(1)+cosh(1)=" << std::log(std::sinh(1)+std::cosh(1)) << '\n';
    // special values
    std::cout << "cosh(+0) = " << std::cosh(0.0) << '\n'
              << "cosh(-0) = " << std::cosh(-0.0) << '\n';
    // error handling
    errno=0;
    std::feclearexcept(FE_ALL_EXCEPT);
    std::cout << "cosh(710.5) = " << std::cosh(710.5) << '\n';
    if (errno == ERANGE)
        std::cout << "    errno == ERANGE: " << std::strerror(errno) << '\n';
    if (std::fetestexcept(FE_OVERFLOW))
        std::cout << "    FE_OVERFLOW raised\n";
}

Possible output:

cosh(1) = 1.54308
cosh(-1) = 1.54308
log(sinh(1)+cosh(1)=1
cosh(+0) = 1
cosh(-0) = 1
cosh(710.5) = inf
    errno == ERANGE: Numerical result out of range
    FE_OVERFLOW raised

sinhsinhfsinhl (C++11)(C++11)	computes hyperbolic sine (${\small\sinh{x} }$ $sinh(x)$ ) (function)
tanhtanhftanhl (C++11)(C++11)	computes hyperbolic tangent (${\small\tanh{x} }$ $tanh(x)$ ) (function)
acoshacoshfacoshl (C++11)(C++11)(C++11)	computes the inverse hyperbolic cosine (${\small\operatorname{arcosh}{x} }$ $arcosh(x)$ ) (function)
cosh(std::complex)	computes hyperbolic cosine of a complex number (${\small\cosh{z} }$ $cosh(z)$ ) (function template)
cosh(std::valarray)	applies the function std::cosh 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)
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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)