Completing the square is often difficult for students to grasp at first. It may take a while. The GSP lab can also be lengthy, so I felt at least two days would be necessary to complete this lesson.
Objectives:
To recognize a quadratic function.
To sketch the graph of a quadratic function.
Materials:
Graphing calculator with overhead
Geometer's Sketchpad
Graph paper
Procedure:
Discuss and define a quadratic function and a parabola.
Graph several quadratic functions on the overhead and talk about what makes the parbola open up or down.
Discuss the completed square form: f(x) = a(x-h)^2 + k
Discuss the vertex.
Explain and give examples on how to complete the square when the leading coefficient is 1.
Explain and give examples on how to complete the square when the leading coefficient is not 1.
Have the students do pg. 641 A, B, C, and D in class. This involves having them sketch the graphs on graph paper.
Give them the worksheet that goes along with the Geometer's Sketchpad activity. If time is short, you can already have the graph on GSP for them.
Click here for the GSP graph.
Classwork/Homework: pg. 642-643 # 6-20 even, 29-35 odd, and 39.