No Slope: An Ambiguous Term
Date: 05/08/2003 at 11:06:00 From: Ashlynne Subject: The distinction of a line What is the distinction between a line with a slope of zero and a line with no slope?
Date: 05/08/2003 at 12:04:45 From: Doctor Peterson Subject: Re: The distinction of a line Hi, Ashlynne. The phrase "no slope" is ambiguous, and should not be used. In everyday English, is means that the line is not sloped, and therefore has zero slope (horizontal); but mathematically, it can be argued that it means the slope is not defined, which happens when the line is vertical. Any ambiguous term is dangerous in math, so it should be banned. The proper terminology is that a horizontal line has zero slope (or slope 0), while a vertical line has undefined (or, informally, infinite) slope. This is because to find the slope of a vertical line you would be dividing by zero, which is not allowed. If you have any further questions, feel free to write back. - Doctor Peterson, The Math Forum http://mathforum.org/dr.math/
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