Answer:
Step-by-step explanation:

not a unit vector.
b.

it is a unit vector.
c.

it is a unit vector.
d.

it is not a unit vector.
13.8 is bigger being a positive number.
Proof:-
In ∆XYZ and ∆VWZ

Hence
∆XYZ
∆VWZ(Side-Angle-Side)
Slope = 0 do answer is y = 1