Question

Let vectors Ā = (2,1,-4), B = (-3,0,1), and C = (-1,-1,2).
Calculate the following:
Vector Ā * Vector B = _______
What is the angle Ɵ AB between vector Ā and vector B?
2 Vector B * 3 Vector C = _________

Answer 1

Vector Ā * Vector B = -10. This is the scalar dot product and can calculated by taking the magnitude in the x, y, and z of the two vectors and the operation is done. 
The angle  Ɵ AB between vector Ā and vector B is 133.635°.
2 Vector B * 3 Vector C = -1. A similar approach is done for this one.