Question

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

Answer 1

what i like to do is to stack the vectors: multiply down the columns, and add the results; this defines their dot product

u = ( 1,-7)
v = (-42,4)
------------
-42 -28

if the result is 0, they are orthogonal (perpendicular)

Answer 2

if their ratio of parts is equal, they are paralell

u = 1 -7
--- ---
v = -42 4

Answer 3

if neither condition holds, then they are ... well, neither