3
practice testMultiple Choice

Practice Test

Question 3 • Algebra: Concepts and Connections

Between which two ordered pairs does the graph of f⁡(x)=12⁢x2+x−9 cross the negative x-axis? Quadratic formula: x is equal to the fraction with numerator negative b plus or minus square root of b squared minus 4 A c end root and denominator 2 A

Answer
A
negative 3 comma 0 and negative 2 comma 0
B
negative 2 comma 0 and negative 1 comma 0
C
negative 4 comma 0 and negative 3 comma 0
D
negative 6 comma 0 and negative 5 comma 0

Explanation

For f(x) = (1/2)x² + x − 9, the x-intercepts occur when f(x) = 0. Using the quadratic formula gives x = (−1 ± √19), so the negative root is about −5.36. That lies between −6 and −5, so the graph crosses the negative x-axis between (−6, 0) and (−5, 0), choice D.

AI-written and checked against the verified answer.

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