QUESTION 15:
What is:
(1, -3)T · (1, -3)T = ?
(-2, 5, -6)T · ( 1, 2, 3)T = (-2)*1 + 5*2 + (-6)*3 = -2 + 10 -18 = -10
The answer is a negative real. This is fine. Dot products produce all kinds of reals: negative, zero, positive. However, something interesting happens when you take the dot product of a vector with itself.
What is:
(1, -3)T · (1, -3)T = ?