11.3: Quadratic Formula
This activity is intended to supplement Algebra I, Chapter 10, Lesson 5.
Problem 1
1. Identify the zeros of
2. You may already know the zero product property, and can demonstrate why the following are the solutions to the equation above:
3. A program, QUAD, is provided that has the Quadratic Formula defined. Use
Problem 2
4. Now, examine the graph of
Use the QUAD program again. You only need to enter in the correct values for
5. What are the solutions to the equation
Problem 3
6. Now, examine the graph of
7. Using the QUAD program, what are the solutions to the equation
Exercise 4
8. Explore
 “Some quadratic equations are not factorable with integers because…”
or
 “Quadratic equations are only factorable with integers when…”
9. Solve the following equations using the QUAD program.

y=x2−2x−7 
y=−3x+x+3
10. Finally, use Lists to calculate the value of the discriminant for the previous two problems, whose solutions were irrational. Enter the

y=x2−2x−7 Solution: __________________ 
y=−3x+x+3 Solution: __________________
Extensions/Homework
Use the formula in

y=x2−6x+9 
y=3x2+4x+5 
y=−4x2+2x+2 
y=7x2+x−8 
y=2x2−5
Look at the flow chart below and discuss with another student how to use it to answer these homework problems.
My Notes/Highlights Having trouble? Report an issue.
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