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std::cosh

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

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";
}

See also

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

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http://en.cppreference.com/w/cpp/numeric/math/cosh