You should be aware of the alternative form of the equation of a circle and how you can find the centre and radius.

Example in the video

Find the centre and radius from the following equation of a circle:

  1. {x^2} + {\rm{ }}{y^2} + {\rm{ }}10x{\rm{ }} - {\rm{ }}12y{\rm{ }} + {\rm{ }}9{\rm{ }} = {\rm{ }}0