Compute the cosine of an angle
Synopsis:
#include <math.h>
double cos( double x );
float cosf( float x );
long double cosl( long double x );
Arguments:
- x
- The angle, in radians, for which you want to compute the cosine.
Library:
libm
Use the -l m option to
qcc
to link against this library.
Description:
These functions compute the cosine of x radians.
Note:
An argument with a large magnitude may yield results with little or no significance.
Returns:
The cosine of x.
When x is +/-Inf, these functions return NaN.
Note:
If an error occurs, these functions return 0, but this is also a valid
mathematical result.
If you want to check for errors, set
errno
to 0, call the function, and then check
errno again.
These functions don't change
errno if no errors occurred.
Examples:
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
int main( void )
{
double value;
value = cos( M_PI );
printf( "value = %f\n", value );
return EXIT_SUCCESS;
}
produces the output:
value = -1.000000
Classification:
ANSI,
POSIX 1003.1
Safety: |
|
Cancellation point |
No |
Interrupt handler |
No |
Signal handler |
No |
Thread |
Yes |