#include <stdio.h>

main() {
	double x, elem, sum;
	int n, i, j;

	printf("Cos(x). Intro \"x n\": ");
	scanf("%lf %d", &x, &n);

	for(i=0, sum=0; i<=n; i++) {
		for(j=1, elem=1; j<=2*i; j++) {
			elem = elem * x/j;
		}
		if (i%2==0) {
			sum = sum + elem;
		} else {
			sum = sum - elem;
		}
		printf("i=%d\tsum=%lf\telem=%lf\n", i, sum, elem);
	}

	printf("Cos(%lf) = %lf\n", x, sum);
}