## anonymous 5 years ago How to find the center and radius given the standard equasion?

1. anonymous

standard equation for a circle?

2. anonymous

For a circle $x^2+y^2+2gx+2fy+c=0$ , center is (-g,-f) and radius is $\sqrt{g^2+f^2-c}$

3. anonymous

Weird I've never seen that form for a circle. In most cases I see it as $ax^2 + b^2= c^2$ where a=b where the radius is$\sqrt{c^2}$

4. anonymous

$ax^2+ by^2=c^2$ woops wrote it wrong.

5. anonymous

Erm.. Standard equation for a circle is $(x-h)^2 + (y-k)^2 = r^2$ If you put multiplicative constants out front that aren't equal you'll end up with an ellipse.

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