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std::cosh, std::coshf, std::coshl - cppreference.com

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Defined in header <cmath>

(1)

float cosh ( float num ); double cosh ( double num ); long double cosh ( long double num );

 (until C++23)

/*floating-point-type*/ cosh ( /*floating-point-type*/ num );

 (since C++23)
(constexpr since C++26)

float coshf( float num );

 (2) (since C++11)
(constexpr since C++26)

long double coshl( long double num );

 (3) (since C++11)
(constexpr since C++26)

SIMD overload (since C++26)

Defined in header <simd>

template< /*math-floating-point*/ V > constexpr /*deduced-simd-t*/<V> cosh ( const V& v_num );

 (S) (since C++26)

Additional overloads (since C++11)

Defined in header <cmath>

template< class Integer > double cosh ( Integer num );

 (A) (constexpr since C++26)

1-3) Computes the hyperbolic cosine of num. The library provides overloads of std::cosh 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 cosine of num (cosh(num), or

) 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 |num| > 710.5, then std::cosh(num) overflows.

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::cosh(num) has the same effect as std::cosh(static_cast<double>(num)).

Example

#include <cerrno>
#include <cfenv>
#include <cmath>
#include <cstring>
#include <iostream>
// #pragma STDC FENV_ACCESS ON

int main()
{
    const double x = 42;

    std::cout << "cosh(1) = " << std::cosh(1) << '\n'
              << "cosh(-1) = " << std::cosh(-1) << '\n'
              << "log(sinh(" << x << ")+cosh(" << x << ")) = "
              << std::log(std::sinh(x) + std::cosh(x)) << '\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(42)+cosh(42)) = 42
cosh(+0) = 1
cosh(-0) = 1
cosh(710.5) = inf
    errno == ERANGE: Numerical result out of range
    FE_OVERFLOW raised

See also

(C++11)(C++11)

 computes hyperbolic sine (sinh(x))
(function) [edit]

(C++11)(C++11)

 computes hyperbolic tangent (tanh(x))
(function) [edit]

(C++11)(C++11)(C++11)

 computes the inverse hyperbolic cosine (arcosh(x))
(function) [edit]
computes hyperbolic cosine of a complex number (cosh(z))
(function template) [edit]
applies the function std::cosh to each element of valarray
(function template) [edit]