# cosh(), coshf(), coshl()

Compute the hyperbolic cosine

## Synopsis:

```#include <math.h>

double cosh( double x );

float coshf( float x );

long double coshl( long double x );
```

## Arguments:

x
The angle, in radians, for which you want to compute the hyperbolic cosine.

## Library:

libm

Use the -l m option to qcc to link against this library.

## Description:

These functions compute the hyperbolic cosine of x radians. A range error occurs if the magnitude of x is too large.

To check for error situations, use feclearexcept() and fetestexcept():

• Call feclearexcept(FE_ALL_EXCEPT) before calling cosh(), coshf(), or coshl().
• On return, if fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is nonzero, then an error has occurred.

## Returns:

The hyperbolic cosine of x. If the correct value would cause an overflow, a range error occurs, and cosh(), coshf(), and coshl() return HUGE_VAL, HUGE_VALF, and HUGE_VALL, respectively.

If x is: These functions return:
NaN NaN
±0 1.0
±Inf ±Inf

## Errors:

FE_OVERFLOW
The result would cause an overflow.

## Examples:

```#include <stdio.h>
#include <math.h>
#include <fenv.h>
#include <stdlib.h>

int main( void )
{
int except_flags;

feclearexcept(FE_ALL_EXCEPT);

printf( "%f\n", cosh(.5) );

except_flags = fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW);
if(except_flags) {
/* An error occurred; handle it appropriately. */
}

return EXIT_SUCCESS;
}
```

produces the output:

```1.127626
```

## Classification:

Safety:
Cancellation point No
Interrupt handler No
Signal handler No