I put a graph on the board using Sketchpad with “obvious” x-intercepts of -2 and 6 (using a slider) and we talked about “roots” and “line of symmetry”. By eyeballing the graph, we found that the vertex had to be at x = 2. Moving the sliders around, we found that the x-intercept of the graph would always be exactly halfway between the roots. We talked about how the average of the two roots would give you that value. We also discussed how we could find its y-value by using the equation, which was the first time that we could actually use the standard form in class due to lack of calculators.
Most of the rest of the lesson we just went back over solving quadratics, then I let them begin their work.
I gave questions 1 – 3, 5 – 6, 10, and 13.
