Question 258586: The ordered pair (-3,2) lies on a circle with center (0,3). What is the equation of the circle? i dont get how to work this problem out can i please get help?
Found 2 solutions by Alan3354, Edwin McCravy:
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! The ordered pair (-3,2) lies on a circle with center (0,3). What is the equation of the circle? i dont get how to work this problem out can i please get help?
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The distance from the point to the center is the radius. Find the distance.
r^2 = diffy^2 + diffx^2
r^2 = 1 + 9 = 10
The distance squared is ok.
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The eqn for a circle of radius r, with its center at (h,k) is:
(x-h)^2 + (y-k)^2 = r^2
--> x^2 + (y-3)^2 = 10
Answer by Edwin McCravy(20086)  (Show Source):
You can put this solution on YOUR website! The ordered pair (-3,2) lies on a circle with center (0,3). What is the equation of the circle? i dont get how to work this problem out can i please get help?
Momorize these two facts:
1. The equation of the circle with center (h,k) and radius, r, is:
(x-h)2 + (y-k)2 = r2
2. The distance, d, between the points (x1,y1) and
(x2,y2) is given by this formula:
Plot those points:
Now if we connect them that will be a radius, and we can draw the circle
by putting the point of a compass on (0,3) and the pencil of the compass
on (-3,2) and swinging it around.
If we find the distance between those two points we will have the radius r.
So we use this formula to find that distance:
where (x1,y1) = (0,3) and (x2,y2) = (-3,2)
Substituting:
So d is the radius r.
Now we are ready to substitute into
 with center  and  .
Edwin
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