6

Set 2: Linear Functions (Advanced)

Explanation

Answer: A

A line passes through (4,1)(4, -1) and (4,5)(4, 5). What is its equation?

A.

x=4x = 4

✓ Correct
B.

y=4y = 4

C.

y=x5y = x - 5

D.

x=1x = -1

Detailed Explanation

Choice A is correct. Choice A is the correct answer. Vertical line check. 1. Check x: Both are 4. 2. Conclusion: Vertical line x=4x = 4. Strategic Tip: If x doesn't change, the equation is x=valuex = \text{value}. Choice B is incorrect because horizontal. Choice C is incorrect because diagonal. Choice D is incorrect because wrong value.

Key Steps:

The correct answer is x=4x = 4

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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