In this optional lesson, students deepen their understanding about the merits and potential drawbacks of using the quadratic formula. They pay close attention to each step in the solving process and analyze errors commonly made when applying the formula. Students also consider how to verify that the solutions they obtain with the quadratic formula are correct.

In analyzing the solution process and checking their work and the work of others, students practice critiquing the reasoning of others (MP3).

Technology isn’t required for this lesson, but there are opportunities for students to choose to use appropriate technology to solve problems. Consider making technology available.