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For f(x) = a(x - h) squared + k, what does a size of a above 1 do to the graph?
AThe graph becomes wider
BThe graph shifts upward
CThe graph becomes narrower
DThe graph shifts sideways
Answer & Solution
Correct answer: C. The graph becomes narrower
1. The number a in front of the squared bracket controls a vertical stretch.
2. A size above 1 pulls every point further from the horizontal axis.
3. So the parabola looks narrower, while a size below 1 makes it look wider.
_Source: OpenStax Precalculus (CC BY 4.0), section 3.2 Quadratic Functions_