Question

Determine whether the vectors u and v are parallel, orthogonal, or neither.

Answer 1

For this case we have the following vectors:
 u = (9, 0)
 v = (0, -9)
 Using product point we have:
 u.v = (9, 0). (0, -9)
 u.v = (9) * (0) + (0) * (- 9)
 u.v = 0 + 0
 u.v = 0
 If the scalar product of two vectors is zero, both vectors are orthogonal.
 Answer:
 C. orthogonal