Download Ch 8 TEST version A - Harlem School District 122

11.1 Solve Quadratics by Graphing
Name ________________________
Learning Objective: A.APR.3
I will find the zeros of a quadratic function from a graph
A.REI.4
I will find the solutions of a quadratic equation by finding the zeros on its graph
F.IF.4
I will identify the zeros of a quadratic graph
F.IF.7
I will graph a quadratic function using a graphing calculator
Solve each equation by showing all work. They will have TWO answers each.
1. x2 = 81
5.
1 2
r = 2
2
2. 121 = n2
6.
3 2
x = 12
4
3. 3p2 = 27
4. –10k2 = –1000
7. k2 – 144 = 0
8. n2 – 0.25 = 0
Estimate the solutions of each equation using the given graph.
9. x2 – 5x = 0
10. x2 + 8x + 16 = 0
11. x2 – 9 = 0
x = _____ or _____
x = _____ or _____
x = _____ or _____
12. x2 – 2x – 8 = 0
13. x2 + 2x – 15 = 0
x = _____ or _____
x = _____ or _____
14. x2 – 3x + 2 = 0
x = _____ or _____
Use the graphing calculator to solve. (Replace 0 with y.) Find the solution. (x – intercepts) If
there are none, write no solution. Round answers to the nearest tenth.
15. x2 + 2x – 8 = 0
16. 2x2 + 7x – 4 = 0
17. –x2 + 9 = 0
18. x2 – 9x + 18 = 0
19. x2 – 8x + 16 = 0
20. 2x2 – 3x + 5 = 0
21. 4x2 – 4x = 15
22. x2 – 4x + 9 = 4
23. x2 + 2x = 9
24. Adrian earned 50 out of 80 points on a test. What percentage did he score on the test?
25.
Write the equation of the axis of symmetry and find the coordinates of the vertex. Identify the
vertex as a maximum or a minimum. Then graph the function.
y = –4x2 – 8x + 5
Vertex: ______
Axis of sym:______
Max or Min: ________
26. The sum of two numbers is 18. The difference of the numbers is 4. Write a system of equations
that models this situation. DO NOT SOLVE.
Variable Used:
Equations:
27. Shawn and Jenny are selling wrapping paper for a school fundraiser. Shawn sold 10 rolls of
plain wrapping paper and 6 rolls of shiny wrapping paper for a total of $168. Jenny sold 13 rolls
of plain wrapping paper and 6 rolls of shiny wrapping paper for a total of $195. Write a system of
equations that models this situation. DO NOT SOLVE.
Variable Used:
Equations:
Answers: 1) x = ±9
3) p = ±3
5) r = ±2
7) k = ±12
9) x = 0 or x = 5
11) x = –3 or x = 3 13) x = –5 or x = 3
15) x = –4 or x = 2 17) x = ±3
19) x = 4
–
–
–
–
21) x = 1.5 or x = 2.5 23) x = 4.2 or x = 2.2
25) ( 1, 9), x = 1, max
10
p

6s  168

27) p = # of plain rolls, s = # of shiny rolls 
13p  6s  195