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#1 Yesterday 02:38:25
Coordinate Geometry Question
Hey guys, hope you are chilling.
I have a question from my Optional Mathematics' coordinate geometry, which has confused me a lot:
## Find the equation of the circle which touches the X-axis at the point (3,0) and cuts off an intercept 8 units from the positive part of the Y-axis.
I tried several attempts but failed. All suggestions are welcomed. 
I know my value. Anyone else’s opinion doesn’t really matter.
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#2 Yesterday 03:52:07
Re: Coordinate Geometry Question
I'm not good at english. I guess "touches the x axis" means it has only one intersection point with the x axis. Is that correct?
Do you know about vertical diameter theorem(the translator called this)? Draw a perpendicular line through the center of the circle to the intercept. The intercept is perpendicularly disseated by the line. Is that helpful?
实迷途其未远，觉今是而昨非。 I did get lost. Maybe I haven't gone too far. Now I have come to realize how wrong I have been all those years.
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#4 Yesterday 05:53:48
- Bob
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- Registered: 2010-06-20
- Posts: 10,788
Re: Coordinate Geometry Question
I think this is the diagram:
From d to e is 8 units so the midpoint is 4 from either end. So you can use Pythagoras to find the radius.
Bob
Children are not defined by school ...........The Fonz
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you! …………….Bob 
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