Algebra I Part 2
Unit 4 Day 2 - Solving Quadratic Equations by Graphing Homework
P. 540-541: 10-36 (Even), 41
Name: _______________________________
Solve each equation by graphing.
10. x2 + 7x + 14 = 0
12. x2 – 16x + 64 = 0
14. x2 + 14x = -49
16. x2 – 10x = -16
18. 2x2 – 16x = -30
20. -3x2 + 2x = 15
Solve each equation by graphing. If integral roots cannot be found, estimate the roots to the nearest tenth.
22. x2 + 2x – 9 = 0
24. x2 + 3x = 18
26. 3x2 = -2x + 7
28. SOFTBALL Sofia hits a softball straight up. The equation h = -16t2 + 90t models the height h, in feet, of
the ball after t seconds. How long is the ball in the air?
Use factoring to determine how many times the graph of each function intersects the x-axis. Identify each
zero.
30. y = x2 – 8x + 16
32. y = x2 + 2x – 24
34. NUMBER THEORY Use a quadratic equation to find two numbers that have a sum of 9 and a product of
20.
36. GOLF The height of a golf ball in the air can be modeled by the equation h = -16t2 + 60t + 3, where h is
the height in feet of the ball after t seconds.
a. How long was the ball in the air?
b. What is the ball’s maximum height?
c. When will the ball reach its maximum height?
41. ERROR ANALYSIS Iku and Zachary are finding the number of real
zeros of the function graphed at the right. Iku says that the function
has no real zeros because there are no x-intercepts. Zachary says
that the function has one real zero because the graph has a yintercept. Is either of them correct? Explain your reasoning.