Task1.c

#include <stdio.h>
#include <math.h>

double vectorMagnitude(int vector[3]);
int dotProduct(int vector[3], int vector2[3]);
double cosCompare(int vector1[3], int vector2[3]);

int main()
{
    int i, j;
    int matrix[4][3] = {
        {1, 4, 6},
        {2, -3, 1},
        {3, 5, 0},
        {3, 1, -3}};

    for (i = 0; i < 3; i++)
    {
        for (j = 1 + i; j < 4; j++)
        {
            printf("%.3f,\n", cosCompare(matrix[i], matrix[j]));
        }
    }

    return 0;
}

double vectorMagnitude(int vector[3])
{
    int sumOfSquares = 0;
    for (int i = 0; i < 3; i++)
    {
        sumOfSquares += vector[i] * vector[i];
    }
    double magnitude = sqrt(sumOfSquares);
    return magnitude;
}

int dotProduct(int vector1[3], int vector2[3])
{
    int dot = 0;
    for (int i = 0; i < 3; i++)
    {
        dot += vector1[i] * vector2[i];
    }
    return dot;
}

double cosCompare(int vector1[3], int vector2[3])
{
    int dot = dotProduct(vector1, vector2);

    double mag1 = vectorMagnitude(vector1);
    double mag2 = vectorMagnitude(vector2);

    double cosine = dot / (mag1 * mag2);
    cosine = acos(cosine);
    return cosine;
}