Set 9: Linear Functions
Explanation
Two lines have slopes and . Are they perpendicular?
No, unless or (with sign change)
Yes, always
No, never
Only if
Detailed Explanation
Choice A is correct. Choice A is the correct answer. Check product rule. 1. Product: . 2. Condition: Perpendicular lines must have a product of . 3. Conclusion: They are reciprocals, but not negative reciprocals. So generally No. Strategic Tip: Don't forget the negative sign! and are perpendicular. Choice B is incorrect because product is 1. Choice C is incorrect because they could be if involves complex numbers (out of scope) or specific sign errors in setup. Choice D is incorrect because undefined.
Key Steps:
The correct answer is No, unless or (with sign change)
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