SOLUTION: write the equation of the circle center: (6,6) radius: (-4,3) ....help?

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Question 37637: write the equation of the circle
center: (6,6)
radius: (-4,3)
....help?
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
You can start with the general form of the equation for a circle whose center is at (h, k) and whose radius is r:
%28x-h%29%5E2%2B%28y-h%29%5E2+=+r%5E2
Applying this to your problem, we first have to find the length of the radius, r. I assume that the coordinates that you have given for the radius are the coordinates of the end-point of the radius. Since the radius of a circle begins at the center of the circle, we need to find the distance between the center (6, 6) and the end-point (-4, 3) using the distance formula:
d=sqrt%28%28x2-x1%29%5E2%2B%28y2-y1%29%5E2%29
d=sqrt%28%28-4-6%29%5E2%2B%283-6%29%5E2%29
d=sqrt%28%28-10%29%5E2%2B%28-3%29%5E2%29
d=sqrt%28100%2B9%29
d=sqrt%28109%29 This is the radius.
But we want r%5E2
r%5E2+=+109
Now for the circle:
%28x-6%29%5E2%2B%28y-6%29%5E2+=+109