First, we are going to rewrite it as a parabola equation. Rewrite. Divide by 8. Factor out coefficient. Then, we are going to convert x into square form. Convert the whole expression into square form. Simplify. Subtract 6 from both sides. Divide by coefficient. Rewrite in standard form.
The radius of the circle will be -2. Also, no matter what the sign says, the radius has to always be positive. Have a nice day! :)