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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

) 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";
}

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