The function f is defined by . The graph of f in the xy-plane is a parabola. Which of the following intervals contains the x-coordinate of the vertex of the graph of f ?
A
B
C
D
Correct answer: B
Explanation
Choice B is correct. The graph of a quadratic function in the xy-plane is a parabola. The axis of symmetry of the parabola passes through the vertex of the parabola. Therefore, the vertex of the parabola and the midpoint of the segment between the two x-intercepts of the graph have the same x-coordinate. Since , the x-coordinate of the vertex is . Of the shown intervals, only the interval in choice B contains –2. Choices A, C, and D are incorrect and may result from either calculation errors or misidentification of the graph’s x-intercepts.
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id cb_question_bank:8051471b-302b-47c8-97c9-c65dd28bb43c · question 70753f99 · IBN 08364-DC
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