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

< cpp‎ | numeric‎ | math
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
earg
+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

#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

See also

(C++11)(C++11)
 computes hyperbolic sine (sinh(x))
(function)
(C++11)(C++11)
 computes hyperbolic tangent (tanh(x))
(function)
(C++11)(C++11)(C++11)
 computes the inverse hyperbolic cosine (arcosh(x))
(function)
computes hyperbolic cosine of a complex number (cosh(z))
(function template)
applies the function std::cosh to each element of valarray
(function template)