#include <stdio.h>
#include <math.h>
#define PI 3.141592653589793

void printVector();
int scalar_product();
int factorial();
double my_cos();


int main () {
	int u[] = {1,-2,3,-4};
	int v[] = {6,7,1,-2};
	int w[] = {5,-4,5,7};
	int i;
	printf ("vector u = ");
	printVector (u,4);
	printf ("vector v = ");
	printVector (v,4);
	printf ("vector w = ");
	printVector (w,4);
	printf ("vector u * v = ");
	printf ("%i\n", scalar_product(u,v,4));
	printf ("vector u * w = ");
	printf ("%i\n", scalar_product(u,w,4));
	printf ("vector v * w = ");
	printf ("%i\n", scalar_product(v,w,4));
	for (i=0;i<7;i++)
		printf ("factorial %i = %i\n", i, factorial (i));
	for (i=0;i<90;i+=10) {
		printf ("my_cos %i = %f\n", i, my_cos (i*PI/180));
		printf ("   cos %i = %f\n", i, cos (i*PI/180));
	}
	printf ("end\n");
	getchar();
	return 0;
}