Question

I am trying to figure the radius of a circle that has the center of (-5,9) and passes through (-7,-6). Please help

Answer 1

I have done distance equation and have \[\sqrt{229}\] But what do I do now to put it in my standard form equation??

Answer 2

My equation looks like this now \[(x+5)^{2}+(y-9)^{2}=\]
Just having trouble with radius

Answer 3

\[(x+5)^{2} +(y-9)^{2}=229\]

Answer 4

So do I just remove the radical from the distance formula?

Answer 5

The distance between the two points (center and point on the circle) is the radius. The equation of a circle is:
\( (x - h)^2 + (y - k)^2 = r^2 \)
So if you have the distance \(\sqrt{229}\), the radius squared is used in the equation, or \(\sqrt{229}^2 = 229\)

Answer 6

Thank you very much!