Question

5

(a)
Let u and v be non-zero vectors such that v is a unit vector. Show that |u•v|<|u|.When does
equality occur? Explain your reasoning.
[3]
(b)
Show that if x and y are non-zero parallel vectors, then X×Y=0.
[2]
(c)
Referred to the origin o, points A and B have position vectors a and b respectively. Let C be a
variable point with position vector 2(a - b). Show that the area of AABC is independent of 2. [2]​

Answer 1

5

(a)

Let u and v be non-zero vectors such that v is a unit vector. Show that |u•v|<|u|.When does

equality occur? Explain your reasoning.

[3]

(b)

Show that if x and y are non-zero parallel vectors, then X×Y=0.

[2]

(c)

Referred to the origin o, points A and B have position vectors a and b respectively. Let C be a