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    Hi, i've managed to do part A, but would like some help with part B of this question. I can't see a way of doing it, because I don't know the point where the tangent and the circle touch. Just need some advice on where to start. Thanks in advance for any help.
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    (Original post by bjt1882)
    Hi, i've managed to do part A, but would like some help with part B of this question. I can't see a way of doing it, because I don't know the point where the tangent and the circle touch. Just need some advice on where to start. Thanks in advance for any help.
    You don't actually need to find the point.

    At the points where the line and the circle meet, the two equations will be satisfied simultaneously.

    So, sub mx+2 for y into your equation for the circle and you'll get a quadratic in x.

    The solutions will be the x-coordinates of the points of intersection.

    But since the line is a tangent, there will be only one solution.

    So, you're looking to find when the quadratic has just one solution.

    Can you finish from there?
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    (Original post by bjt1882)
    Hi, i've managed to do part A, but would like some help with part B of this question. I can't see a way of doing it, because I don't know the point where the tangent and the circle touch. Just need some advice on where to start. Thanks in advance for any help.
    If its tangent, then there is a single solution to the eq in part a. And since there is only a single solution, then that means the discriminant is...?
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    (Original post by ghostwalker)
    You don't actually need to find the point.

    At the points where the line and the circle meet, the two equations will be satisfied simultaneously.

    So, sub mx+2 for y into your equation for the circle and you'll get a quadratic in x.

    The solutions will be the x-coordinates of the points of intersection.

    But since the line is a tangent, there will be only one solution.

    So, you're looking to find when the quadratic has just one solution.

    Can you finish from there?
    (Original post by RDKGames)
    If its tangent, then there is a single solution to the eq in part a. And since there is only a single solution, then that means the discriminant is...?
    Yeah I got it, thanks for the help
 
 
 
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