3

Set 4: Quadratic Equations

Explanation

Answer: A

Find the x-intercepts of y=2x28y = 2x^2 - 8.

A.

(±2,0)(\pm 2, 0)

✓ Correct
B.

(4,0)(4, 0)

C.

(±4,0)(\pm 4, 0)

D.

(2,0)(2, 0)

Detailed Explanation

Choice A is correct. Choice A is the correct answer. Set y=0y=0 and solve for x. 1. 2x28=02x^2 - 8 = 0. 2. Add 8: 2x2=82x^2 = 8. 3. Divide by 2: x2=4x^2 = 4. 4. Square root: x=±2x = \pm 2. Choice B is incorrect because it forgets square root. Choice C is incorrect because it forgets to divide by 2. Choice D is incorrect because it misses negative root.

Key Steps:

The correct answer is (±2,0)(\pm 2, 0)

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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