Ni#1

#include "stdafx.h"
#include <iostream>
#include <cmath>


using namespace std;



void main()
{
    int A[10] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
    int B[10] = { 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 };
    int scalar = 0;
    double absa = 0, absb = 0;
    for (int i = 0; i < 10; i++) {
        scalar += A[i] * B[i];
        absa += A[i] * A[i];
        absb += B[i] * B[i];
    }
    absa = sqrt(absa);
    absb = sqrt(absb);
    cout << "cosY = " << (scalar * 1.0) / (absa * absb) << endl;
    system("pause");
}