cos

INTERFACE

#include <math.h>

double cos ( double x ) long cosl ( long double x ) float cosf ( float x )

#include <complex.h> double complex ccos(double complex z) long double complex ccosl(long double complex z) float complex ccosf(float complex z)

DESCRIPTION

The cos function computes the cosine of x (measured in radians). It returns a value in the range of -1 to 1.

The complex cosine is defined by

(1)

#include <stdio.h>
#include <math.h>
 
int main()
{
  double x = 1.047198;
  double result = cos(x);
  printf("The cosine of %lf is %lf\n", x, result);
  return 0;
}

The cosine of 1.047198 is 0.500000

SPECIAL VALUES

cos ( 0 ) returns 1.
cos ( &infin; ) returns a NaN and raises the invalid floating-point exception.

SEE ALSO

sin, tan, asin, acos, atan, atan2, sinh, cosh, tanh

STANDARDS

The cos function conforms to ISO/IEC 9899:1999(E).