9

Set 9: Quadratic Equations (Advanced)

Explanation

Answer: A

If the vertex of a parabola is (3,5)(3, 5) and it opens upward, what is the range of the function?

A.

y5y \geq 5

✓ Correct
B.

y5y \leq 5

C.

y3y \geq 3

D.

All real numbers

Detailed Explanation

Choice A is correct. Choice A is the correct answer. 1. The vertex is (3,5)(3, 5), so the minimum y-value is 5. 2. Since it opens upward, the graph goes up to infinity from 5. 3. Therefore, the range is all y-values greater than or equal to 5 (y5y \geq 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).

Key Steps:

The correct answer is y5y \geq 5

Why others are wrong:
B: Choice B is incorrect and may result from a calculation error.
C: Choice C is incorrect and may result from a calculation error.
D: Choice D is incorrect and may result from a calculation error.

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