Deeboss
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Yyjvyj
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RDKGames
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(Original post by Deeboss)
Suppose a 2D line passes through two points P0(10, 15) and P1(200, 20). Answer Questions 7 *- 10 regarding this line.

Question 7) Which of the following vectors parallel to the line?

(180, *10)

(190, 5)

(*380, *10)

(*180, 10)

I AM NOT WANTING AN ANSWER. I am hoping someone can take some time to explain to me how to work this out. I have searched online around this topic, and havent seemed to find much unless I am searching the wrong thing. I know this is about placement lines in vectors. So far what I think is I am meant to draw a 200x200cm grid, plot all the answers and see what is parallel to the two points P0(10, 15) and P1(200, 20)?

All explanations and help is much appreciated.
You don't need to draw a 200x200 grid.... Just find what the vector from P_0 to P_1 is and take the answer which is a multiple of it.
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Deeboss
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(Original post by RDKGames)
You don't need to draw a 200x200 grid.... Just find what the vector from P_0 to P_1 is and take the answer which is a multiple of it.
Wait how do i find the vector of p0, and p 1? Could you like give me a worked example.
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Deeboss
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(Original post by Mr Moon Man)
It's (190,5)
The equation of the line is r=(10,15) +lambda(190,5)
How did you find the equation of the line? Can you give me a worked example please?
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RDKGames
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(Original post by Deeboss)
Wait how do i find the vector of p0, and p 1? Could you like give me a worked example.
By doing P_1-P_0 which a basic vector property which you should know
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B_9710
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For two vectors to be parallel, they have to be scalar multiples of each other i.e. If  \mathbf{a} and  \mathbf{b} are vectors then  \mathbf{a}=c\mathbf{b} for some scalar  c .
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Deeboss
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(Original post by RDKGames)
By doing P_1-P_0 which a basic vector property which you should know
So if I want to work out the vector that is perpendicular to the line would I have to do 20-15 = 5
200-10 = 190

(5,190)?
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RDKGames
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(Original post by Deeboss)
So if I want to work out the vector that is perpendicular to the line would I have to do 20-15 = 5
200-10 = 190

(5,190)?
No.

A perpendicular vector would one named \mathbf{v} such that \mathbf{a} \cdot \mathbf{v}=0 where \mathbf{a} is your parallel vector.

For a vector A=[x,y] you would have perpendicular vector A'=[-y,x] for some x,y.
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B_9710
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What level are you at, GCSE or A level? If so what module are you doing it in?
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Deeboss
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(Original post by B_9710)
What level are you at, GCSE or A level? If so what module are you doing it in?
I only did up to GCSE maths, and got a C.

The uni module I am doing is Quantitative method for computing.

FYI: Im not so great at maths, but I putting in MAX effort on my coursework.
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