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    "The vector equation of the line through the point A(2,3) in the direction of the vector 2i+4j can be written as?"
    I got y=2x-1 but not sure if it is right or not.
    How would you solve this type of question asking for equation of a vector like this? (i.e: parrallel or in the same direction)
    Thanks
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    (Original post by prepdream)
    "The vector equation of the line through the point A(2,3) in the direction of the vector 2i+4j can be written as?"
    I got y=2x-1 but not sure if it is right or not.
    How would you solve this type of question asking for equation of a vector like this? (i.e: parrallel or in the same direction)
    Thanks
    Does the question specific whether you need to write the vector equation or Cartesian equation down?
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    (Original post by B_9710)
    Does the question specific whether you need to write the vector equation or Cartesian equation down?
    No, just vector equation in general so I think both is fine
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    (Original post by prepdream)
    "The vector equation of the line through the point A(2,3) in the direction of the vector 2i+4j can be written as?"
    I got y=2x-1 but not sure if it is right or not.
    How would you solve this type of question asking for equation of a vector like this? (i.e: parrallel or in the same direction)
    Thanks
    If line contains the point with position vector \mathbf{a} and is parallel to \mathbf{b} then you can write it as r = \mathbf{a} + \lambda \mathbf{b}
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    (Original post by Zacken)
    If line contains the point with position vector \mathbf{a} and is parallel to \mathbf{b} then you can write it as r = \mathbf{a} + \lambda \mathbf{b}
    Thanks. What about the type of question about "in the direction of...", how would you solve it?
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    (Original post by prepdream)
    "The vector equation of the line through the point A(2,3) in the direction of the vector 2i+4j can be written as?"
    I got y=2x-1 but not sure if it is right or not. Correct
    How would you solve this type of question asking for equation of a vector like this? (i.e: parrallel or in the same direction)
    Thanks
    If you mean working backwards, ie starting with y = 2x - 1, then:

    You know the gradient is 2, and a point on the line is x=2, y = 3 (by plugging them into the above).

    Now, r = (2,3) + λ(2,1)
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    (Original post by Bath_Student)
    If you mean working backwards, ie starting with y = 2x - 1, then:

    You know the gradient is 2, and a point on the line is x=2, y = 3 (by plugging them into the above).

    Now, r = (2,3) + λ(2,1)
    OP, ignore this - it's wrong.
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    (Original post by prepdream)
    Thanks. What about the type of question about "in the direction of...", how would you solve it?
    "in the direction of..." = parallel to, so same thing. If it's in the direction of \mathbf{b} and contains \mathbf{a} then you can write it as r = \mathbf{a} + \lambda \mathbf{b}
 
 
 
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