std::cosh,std::coshf,std::coshl(3)

NAME
std::cosh,std::coshf,std::coshl - std::cosh,std::coshf,std::coshl

Synopsis
   Defined in header <cmath>
   float cosh ( float num );
   double cosh ( double num ); (until C++23)
   long double cosh ( long double num );
   /* floating-point-type */ (since C++23)
               cosh ( /* floating-point-type */ num ); (constexpr since C++26)
   float coshf( float num ); (1) (2) (since C++11)
                        (constexpr since C++26)
   long double coshl( long double num ); (3) (since C++11)
                        (constexpr since C++26)
   Additional overloads (since C++11)
   Defined in header <cmath>
   template< class Integer > (A) (constexpr since C++26)
   double cosh ( Integer num );
   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 (since C++11)
   treated as double.

Parameters
   num - floating-point or integer value

Return value
   If no errors occur, the hyperbolic cosine of num (cosh(num), or
   enum
   +e-num
   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 |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
// Run this code
 #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
   sinh
   sinhf computes hyperbolic sine (\({\small\sinh{x}}\)sinh(x))
   sinhl (function)
   (C++11)
   (C++11)
   tanh
   tanhf computes hyperbolic tangent (\({\small\tanh{x}}\)tanh(x))
   tanhl (function)
   (C++11)
   (C++11)
   acosh
   acoshf computes the inverse hyperbolic cosine
   acoshl (\({\small\operatorname{arcosh}{x}}\)arcosh(x))
   (C++11) (function)
   (C++11)
   (C++11)
                       computes hyperbolic cosine of a complex number
   cosh(std::complex) (\({\small\cosh{z}}\)cosh(z))
                       (function template)
   cosh(std::valarray) applies the function std::cosh to each element of valarray
                       (function template)
   C documentation for
   cosh