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advanced-mathIf the vertex of a parabola is and it opens upward, what is the range of the function?
A
B
C
D
All real numbers
Correct Answer: A
Choice A is the correct answer.
- The vertex is , so the minimum y-value is 5.
- Since it opens upward, the graph goes up to infinity from 5.
- Therefore, the range is all y-values greater than or equal to 5 ().
Choice B is incorrect because that would be for a parabola opening downward. Choice C is incorrect because it uses the x-coordinate. Choice D is incorrect because the range of a quadratic is never all real numbers (the domain is).