MY REFLECTIONS (over line l)
The equation of a circle is a very nice connection between the two worlds... geometry and algebra. Quickly we see how by moving from the generic plane to the coordinate grid that we are able to analyze things much more thoroughly. We are able to derive equations, plot circles, and determine facts about the circles.
I teach this unit (unit #4) after unit #5 because I like to do all of the circle properties and relationships first and then move to the coordinate grid. This makes an easy transition from unit to unit as well.
Teaching completing the square is also review for them but many struggle with it so I work backwards using binomial multiplication first.