1. Lesson 3

1.10. Lesson 3 Summary

Mathematics 20-2 M3 Lesson 3

Module 3: Quadratics

 

Lesson 3 Summary

 

This is an image of a calculator with a parabola on the screen. The minimum value of the parabola is indicated on the screen.

In this lesson you investigated how the graphing calculator can be used as a tool to help solve problems modelled by quadratic functions. You found that you could enter a quadratic function into a graphing calculator by pressing the Y= key. Once the function was entered, you could see the graph by pressing the GRAPH key. You learned how to adjust the scale and the amount of the graph shown by changing the values displayed when the WINDOW key was pressed.

 

You also learned that points on the graph, such as the coordinates of the vertex and the x- and y-intercepts, could be identified using the TRACE key. It also enabled you to find values on the graph that were approximately close to the points you were interested in.

 

Using the CALCULATE feature, you could input values for x and the calculator would tell you the corresponding y-values. Using this feature, you could find exact values for the x-intercepts and maximum or minimum points with ease.

 

By applying the characteristics of quadratic functions you learned in Lessons 1 and 2, you could ensure that the graph you were seeing on the calculator was a reasonable representation of the function.

 

In the next lesson you will investigate other forms of the quadratic function, besides the standard form y = ax2 + bx + c, which you are now familiar with.