This equation is the same as the general equation of a circle, it's just written in a different form. Example Find the equation of the circle with centre \((2, - 3)\) and radius \(\sqrt 7\).

Solving quadratic equations - Edexcel Graphs of quadratic functions. ... Draw the graph of \(y = x^2 -x – 4 \) and use it to find the roots of the equation to 1 decimal place.