# Scalar Multiplication

• Jan 19th 2011, 02:21 PM
Scalar Multiplication
Use the diagram to express each of the given vectors in terms of OP and OQ.

a) OR
b) OU
c) OW
d) OS
e) OA
f) OY

Please any help on how to begin this is really appreciated.
• Jan 19th 2011, 02:35 PM
pickslides
Quote:

Use the diagram to express each of the given vectors in terms of OP and OQ.

a) OR

I get

OR = OP +PR

OR = OP +1/2 PS

As PS = OR then

OR = OP +1/2 OR

Do you follow?
• Jan 19th 2011, 02:57 PM
Yes I think so!

So then:
OU = OP + PU
OU = OP + 2OQ

But then?

OW = OP + 2OP?
• Jan 19th 2011, 03:19 PM
pickslides
Quote:

So then:
OU = OP + PU
OU = OP + 2OQ

Yep!

Quote:

But then?

OW = OP + 2OP?

Nah, I say

OW = OQ + QX +XW

OW = OQ + 2OP + 1/2 OQ

OW = 2OP+3/2 OQ
• Jan 22nd 2011, 05:23 AM
HallsofIvy
Looking at your picture, I see that OR goes down exactly as much as OP and to the right half as much as OQ. That tells me that OR= OP+ (1/2)OQ.

I see that OS goes down as far as OP and to the right as far as OQ: OS= OP+ OQ.

I see that OA and OW both extend down twice as far as OP so both will require "2OP". OA extends as far to the right as OQ while OW extends to the right 3/2 as far as OQ.

OY extends downward three times as far as OP and to the right exactly as far as OQ. OY= what?