Hi all,

Prove that, for any value of c, the circle whose equation is $\displaystyle (x+c)^2+(y-c)^2=c^2$ touches both the x-axis and the y-axis.

Is it enough here to show that $\displaystyle b^2-4ac=0$ when either linear equation $\displaystyle x=0, y=0$ is plugged into the the circle equation.

discriminant in both cases is $\displaystyle 4c^2-4c^2=0$

or is this incorrect?

thanks sammy