#include <stdio.h>
#include <stdlib.h>

int main()
{
    float pow=2, nr, dr=1, x1, sum=1, x;
    int i = 1,n,s = -1;
    printf("Introducir angulo (rad): \n");
    scanf("%f", &x);
    printf("Introducir numero entero para determinar la precision: \n");
    scanf("%d",&n);

    nr = x*x;

    while(i<=n)
    {
        dr = dr * pow * (pow - 1.0);
        sum = sum + (nr / (dr * s));
        s = s * (-1);
        pow = pow + 2.0;
        nr = nr * x * x;
        i++;
    }

    printf("THE SUM OF THE COS SERIES IS: %f", sum);

    return (EXIT_SUCCESS);
}