Which of the following quadratic equations is represented in the graph above?
A. y = x2 - x - 6
B. y = x2 + x - 12
C. y = x2 + 6x + 9
D. y = x2 + 5x + 6
Answer:A
Which of the following quadratic equations is represented in the graph above?
A. y = x2 - x - 6 B. y = x2 + x - 12 C. y = x2 + 6x + 9 D. y = x2 + 5x + 6
Explanation: A Find a point on the graph and plug that point into each of the answers to see which equation works. The graph goes through the point (0, -6). Using that point, (A) becomes -6 = 02 - 0 -6. Solve the right side of the equation to get -6 = -6. Keep (A), but check the remaining answer choices just in case. Choice (B) becomes -6 = 0 + 0 -12. Solve the right side of the equation to get -6 = -12. This is not true, so eliminate (B). Choice (C) becomes -6 = 02 + 6(0) + 9. Solve the right side of the equation to get -6 = 9. Eliminate (C). Choice (D) becomes -6 = 02 + 5(0) + 6. Solve the right side of the equation to get -6 = 6. Eliminate (D). The correct answer is (A).