Question

If "u = (2,2,-1)", "v = (3,-1,0)" and "w = (1,7,8)", verify that "u (dot) (v + w) = u (dot) v + u (dot) w".

My work:

LHS:
u (dot) (v + w)
= (2,2,-1) (dot) (4,6,8)
= [(2,2,-1) (dot) (3,-1,0)] + [(2,2,-1) (dot) (1,7,8)]
= [u (dot) v] + [u (dot) w]
Therefore, LHS = RHS

Did I prove this question correctly?

Answer 1

You should calculate the numerical values for each side and show that thay are the same.
12 (left side)= 4 + 8 (right side)

Although the give you specific numerical values for u, v and w, the relationship is true in general.