### cos -- Calculate Cosine

Format

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

Language Level: ANSI, POSIX, XPG4
cos 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 may occur.

Return Value
cos returns the cosine of x.

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);

       /***************************************
          The output should be:

          cos( 7.200000 ) = 0.608351
       ***************************************/
    }

acos -- Calculate Arccosine
cosh -- Calculate Hyperbolic Cosine
_facos -- Calculate Arccosine
_fcos -- Calculate Cosine
_fcossin -- Calculate Cosine and Sine
_fsincos -- Calculate Sine and Cosine
sin -- Calculate Sine
sinh -- Calculate Hyperbolic Sine
tan -- Calculate Tangent
tanh -- Calculate Hyperbolic Tangent
<math.h>