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    (Original post by madfish)
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    It looks like a midpoint. But only from what you posted, I think it can't be concluded.
    What do they say in the exercise? (Or example, whatever it is)
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    (Original post by madfish)
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    What's the original question?
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    the first picture doesnt work
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    (Original post by purplemind)
    It looks like a midpoint. But only from what you posted, I think it can't be concluded.
    What do they say in the exercise? (Or example, whatever it is)
    yea, it's a mid point, but I dont see how by dividing it by 2 they get b or 2a? is it correct?
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    (Original post by madfish)
    yea, it's a mid point, but I dont see how by dividing it by 2 they get b or 2a? is it correct?
    I don't know either, if would be useful if you posted the original question.
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    (Original post by joostan)
    What's the original question?
    yea, it's a mid point, but I dont see how by dividing it by 2 they get b or 2a? is it correct?
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    (Original post by purplemind)
    I don't know either, if would be useful if you posted the original question.
    we don't need it but :P i am just checking to see if the division by 2 is correct?
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    (Original post by madfish)
    yea, it's a mid point, but I dont see how by dividing it by 2 they get b or 2a? is it correct?
    We can see its a mid point but we haven't got enough information to help you. . .
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    (Original post by joostan)
    We can see its a mid point but we haven't got enough information to help you. . .
    I am just not sure about that division by 2. I didn't get b or 2a when I did it... how does it work? We dont need the question
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    (Original post by madfish)
    I am just not sure about that division by 2. I didn't get b or 2a when I did it... how does it work? We dont need the question
    The division of (2a - 4)/2 does not give 2a unless a = -2
    Similarly the division of b can give the given result but only for a specific value of b
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    (Original post by joostan)
    The division of (2a - 4)/2 does not give 2a unless a = -2
    Similarly the division of b can give the given result but only for a specific value of b
    okay then the solution bank is not correct...
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    (Original post by madfish)
    okay then the solution bank is not correct...
    Depends on the question. If it said given this is true find b, then yes the bank is correct.
    The solution then goes on to do this and find b.
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    (Original post by madfish)
    okay then the solution bank is not correct...
    Why don't you post the original question so we can see what you're being asked to work out? It looks like they've calculated the midpoint of a line joining two points and then set this equal to some other point, which allows them to solve for b and a. However, unless you tell us what this other point is supposed to be, no-one can give you a proper answer!
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    (Original post by davros)
    Why don't you post the original question so we can see what you're being asked to work out? It looks like they've calculated the midpoint of a line joining two points and then set this equal to some other point, which allows them to solve for b and a. However, unless you tell us what this other point is supposed to be, no-one can give you a proper answer!
    The points V(−4,2a) and W(3b,−4) lie on the circle centre (b,2a) . The line VW is a diameter of the circle. Find the value of a and b.
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    (Original post by madfish)
    The points V(−4,2a) and W(3b,−4) lie on the circle centre (b,2a) . The line VW is a diameter of the circle. Find the value of a and b.
    There's the gem!
    The midpoint of the diameter VW = the centre of the circle (b,2a) so you do as the solution bank says to find a and b
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    (Original post by madfish)
    The points V(−4,2a) and W(3b,−4) lie on the circle centre (b,2a) . The line VW is a diameter of the circle. Find the value of a and b.
    Since VW is a diameter, then the midpoint is a circle centre (V and W have the same distance from the centre - which is your midpoint too).
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    (Original post by joostan)
    There's the gem!
    The midpoint of the diameter VW = the centre of the circle (b,2a) so you do as the solution bank says to find a and b
    but their division by 2 is surly not correct?:confused:
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    (Original post by joostan)
    There's the gem!
    The midpoint of the diameter VW = the centre of the circle (b,2a) so you do as the solution bank says to find a and b

    (Original post by purplemind)
    Since VW is a diameter, then the midpoint is a circle centre (V and W have the same distance from the centre - which is your midpoint too).
    We got there in the end
 
 
 
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