This video lesson serves two goals. The first is to relate the work in previous video lessons on quadratic expressions back to the quadratic functions that represent situations. Now students have additional insights that enable them to show (algebraically) that two different expressions can define the same function.

The second goal is to prompt students to notice connections between different forms of quadratic expressions and features of the graphs that represent the expressions. Students are asked to identify the x- and y-intercepts of graphs representing expressions in standard and factored form. They observe that some numbers in the expressions are related to the intercepts and hypothesize about the patterns they observe. (MP7). This work sets the foundation for upcoming lessons, in which students look more closely at how the parameters of quadratic expressions are related to their graphs.

Algebra 1, Episode 9: Unit 6, Lesson 10 | Illustrative Math