NAME¶

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

Synopsis¶

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

// Run this code

#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¶

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)