#include <stdio.h>

int main ()
{
    int h, f, i,sum;
    double t, yuxian,x, m;
    sum = 1;
    f = 2;
    printf("请输入弧度数:");
    scanf("%d", &x);

    yuxian = 0;
    t = h = 1;
    while (t >= 1e-6)
    {
        yuxian += t * h;
        for (i = 1; i <= f; i++)
        {
            sum *= i;
        }
    h *= -1;
    m = x * x;
    t = m / sum;
    f += 2;
    }
    printf("cos(%lf) = %lf\n", x, yuxian);
    return 0;

}