Please help!!! Write the equation of the circle that satisfies this condition: The endpoints of a diameter are at (-2,-3) and and at (4,5)
@ParthKohli @ganeshie8 @Hero @dan
If you have the endpoints of the diameter of a circle, the center of the circle can be found using the midpoint formula, correct?
(x+2)(x-4)+(y+3)(y-5)=0
is that x1+x2/2 and y1+y2/2?
i got (1,1)
yes
(x+2)(x-4)+(y+3)(y-5)=0 is the required equation
Very good. Now find the radius. The radius is the length from one of the endpoints to the center point of the circle.
if the ends of diameter have coordinates (a,b) and (c,d ) then equation of circle is (x-a)(x-c)+(y-b)(y-d)=0
so can I use (1,1) and (4,5)? the distance between these?
@Hero
Yes, you can use the distance formula to find the distance between those two points.
Afterwards you'll have the radius \(r\) and the center \((h,k)\). From there, you can insert those values in to the equation of a circle: \((x - h)^2 + (y - k)^2 = r^2\)
so radius is 5? or is it 5 squared?
You calculated r already? Can you show please the work you did to calculate \(r\) if you don't mind?
|dw:1403076590784:dw|
That looks good. So what do you believe is the equation of the circle?
|dw:1403076811348:dw|
The the left side is equal to \(r^2\) not just \(r\).
so its 25
So the equation of the circle is...?
\[(x-1)^{2}+(y-1)^{2}=25\]
Excellent work.
Thank you for your help!!!
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