Lesson 8
1. Lesson 8
1.8. Lesson 8 Summary
Module 3: Quadratics
Lesson 8 Summary
© Melissa Schalke/7021195/Fotolia
In this lesson you investigated the following questions:
- How can you solve a quadratic equation without using factoring or graphing?
- How can you use the discriminant to find the number of roots a quadratic function will have?
- How do you solve problems using the quadratic formula?
You found that the discriminant, b2 − 4ac, can give you information about the quadratic function y = ax2 + bx + c.
- If the discriminant equals zero, there will be one root or one x-intercept on the graph.
- If the discriminant is positive, there will be two roots or two x-intercepts on the graph.
- If the discriminant is negative, there will be no roots or no x-intercepts on the graph.
- If the discriminant is a perfect square, the function can be factored.
You worked with the quadratic formula, 
, using the formula to find roots of quadratic equations in the form 0 = ax2 + bx + c. For some problems, only one of the roots is admissible because the other does not make sense in the situation.
You learned to apply the quadratic formula to various scenarios to solve problems. You calculated how long a snowboarder was in the air and how far and how high the boarder jumped. You were also able to answer questions about maximizing profits.
In the last lesson in Module 3 you will practise applying many of the skills you learned to practical situations.