$ 1C4 3. For the vectors a = [2, - 1, - 2] and b = [3, - 4, 12], determine the following: a) the angle between the two vectors [2] coso = alt 2 . 3 + (- 17 (-47+ (2) (i) 14 14 allol lal 161 coso = - 14 39 0 = cos - 14 39 = 1 11.030 b) the vector projection of a on b [2] Projection formula proja = a. 6 0 - 14 6. 6 = =14 . [ 3 , - 4, rd ) 4+ 16+ 144 164 292 56 1641 164 / - 168 164 c) a vector that is perpendicular to both a and b Cross product [2] 4. Consider AXYZ for X(3, 1), Y(- 2, 3) and Z(5, 6). Determine if the triangle is a right-angled triangle. Justify your answer. [3]