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Math Help - Question on coordinate geometry of circles

  1. #1
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    Question on coordinate geometry of circles

    Hi, I'm currently doing AS-level Maths in the UK, and I'm struggling with this question on coordinate geometry of circles:

    A circle passes through the points (0, -3) and (0, 3) and has radius 5. Draw a sketch to show the two possible positions of the circles and find their equations.

    Any help would be greatly appreciated!
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    Quote Originally Posted by sakuraxkisu View Post
    Hi, I'm currently doing AS-level Maths in the UK, and I'm struggling with this question on coordinate geometry of circles:

    A circle passes through the points (0, -3) and (0, 3) and has radius 5. Draw a sketch to show the two possible positions of the circles and find their equations.

    Any help would be greatly appreciated!
    Things we know. The equation of a circle is given by the formula

    (x-h)^2+(y-k)^2=r^2 Since we know r we get

    (x-h)^2+(y-k)^2=25
    Since we know two points that lie on the circle we can plug them in for (x,y) and this will give a system of equations in two unknowns that you can solve for h and
    k.

    Can you finish from here?
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  4. #4
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    Thank you! I was on the right tracks, with the substitution of (0, -3) and (0, 3) into the equation, but thank you for clarifying
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