Students will complete the Do Now in 5 minutes. We will then review the answers as a whole group. The task is simple, but it is intended to give my students a hint as to our use of intercepts in today's lesson.
Next, a student will read the objective, "SWBAT sketch a quadratic function using its intercepts".
Before we begin I will ask a student volunteer to summarize the information learned in our last class during the Quadratics Investigation.
In today's lesson students will graph quadratic functions on the coordinate plane without the use of a table.
There are multiple processes involved in graphing quadratic functions. Rather than overwhelm students with too much too soon - today we will focus solely on the x and y axis. Expanding students knowledge of linear functions, we will apply our understanding of the coordinate plane to find the intercepts of the function.
Using this handout, Page 1 will be introduced important terminology and the standard form of a quadratic equation. I will model the identification of coefficients A, B and C in a quadratic function. Additionally I will model how to transform these functions into standard form so that A B and C are easily recognizable. (Students practiced this skill during a previous lesson on Literal Equations).
Next, we will complete the investigation on Page 2 as a whole class. I will use use this website to display a graphing calculator on the board for the class to view. The graph is best displayed using the projector mode option found in settings.
Pairs will work individually to label and factor each trinomial. After a few minutes, students will share their responses aloud as a whole group.
Next, I will input the equation of each function on the screen. After graphing each example, I will ask students to meet careful observations about what is seen on the screen:
Next, students will work in pairs to find all intercepts in the example problems on Page 5. After 15 minutes we will review responses as a whole group. I will graph 6-7 example problems from this page using the Desmos calculator to solidify the relationship between the factors of a quadratic function and its intercepts.
For additional practice with graphs of quadratic functions, my students will work with a partner to complete this Matching Activity. Each graph on Page 1 will match to a quadratic function on Page 2. This activity does not need to be cut up. On Page 2, students should identify and explain the x and y intercepts of each function inside of each box.
We will review this activity as a whole group towards the end of class.
To close today's lesson the class will complete the Closing Activity. This activity may seem redundant - but it is important that students enter our next class with the concepts learned during our investigation as background knowledge. If students are able to find the x and y intercepts of a quadratic function fluently, the addition of more components to the graph will not seem as daunting.
We will review the responses as a whole group to the closing activity as a whole group. Students will then complete an exit card.