Given that a=3i-2j, b=3i+j and c=-6i+j, express pa-qb in terms of p,q,i and j. Hence, find the value of p and of q if pa-qb is equal to the unit vector along the straight line 4x+3y=12

Printable View

- May 14th 2013, 05:51 AMTrefoil2727Vector..
Given that a=3i-2j, b=3i+j and c=-6i+j, express pa-qb in terms of p,q,i and j. Hence, find the value of p and of q if pa-qb is equal to the unit vector along the straight line 4x+3y=12

- May 14th 2013, 06:08 AMPlatoRe: Vector..
- May 16th 2013, 11:13 PMTrefoil2727Re: Vector..
well, I have to admit that I don't know how to solve it..

- May 16th 2013, 11:22 PMMINOANMANRe: Vector..
Trefoil it is simple...

what pa means?

what qb means?

multiplicationnnnn..........so as Plato suggests........ just do itttttttttttttttttttttt .

then we can help you for the last part... - May 17th 2013, 08:10 AMHallsofIvyRe: Vector..
You are told exactly what to do: you are given pa+ qb and you are told that a= 3i-2j, b=3i+j. It's just integer arithmetic.

- May 30th 2013, 11:08 PMmillakinrossRe: Vector..
this interesting

____________________

bachelor party | bucks nights - Jun 8th 2013, 03:07 AMjacobpittRe: Vector..
Really good one question and i don't solve this question and if you know the answer just share with me.

- Jun 8th 2013, 05:13 AMHallsofIvyRe: Vector..Quote:

Given that a=3i-2j, b=3i+j and c=-6i+j, express pa-qb in terms of p,q,i and j. Hence, find the value of p and of q if pa-qb is equal to the unit vector along the straight line 4x+3y=12

A vector pointing along the straight line 4x+ 3y= 12 is 4i+ 3j which has length $\displaystyle \sqrt{4^2+ 3^2}= 5$ so a unit vector in that direction is (4/5)i+ (3/5)j

We have (3p- 3q)i- (2p+ q)j= (4/5)i+ (3/5)j so solve 3p- 3q= 4/5 and -2p- q= 3/5 for p and q.