Question

Please help Fan + Medal

Answer 1

\[x^2+y^2+2gx+2fy+c=0\]
Here center is (-g,-f)
and \[radius=\sqrt{g^2+f^2-c}\]
if center remains the same and radius decreases what you can say from this formula.

Answer 2

are you here?

Answer 3

Yeah I'm just trying to make sense of it, it's all very foreign to me

Answer 4

when you simplify \[when~ you~ complete~the~\square,you~get~this~formula\]
here if g and f are same then to decrease the radius c should be more.

Answer 5

\[\left( x^2+2 gx+g^2 \right)+\left( y^2+2 fy+f^2 \right)+c=g^2+f^2\]
\[\left( x+g \right)^2+\left( y+f \right)^2=g^2+f^2-c=\left( \sqrt{g^2+f^2-c} \right)^2=r^2\]
center is -g,-f and radius \[r=\sqrt{g^2+f^2-c}\]