cos() — Calculate Cosine

Format

#include <math.h>
double cos(double x);

Language Level

ANSI

Threadsafe

Yes

Description

The cos() function calculates the cosine of x. The value x is expressed in radians. If x is too large, a partial loss of significance in the result might occur.

Return Value

The cos() function returns the cosine of x. The value of errno can be set to either EDOM or ERANGE.

Example

This example calculates y to be the cosine of x. 
#include <math.h>
#include <stdio.h>
 
int main(void)
{
   double x, y;
 
   x = 7.2;
   y = cos(x);
 
   printf("cos( %lf ) = %lf\n", x, y);
}
 
/*********************  Output should be similar to:  *******************
 
cos( 7.200000 ) = 0.608351
*/

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