Never discuss mathematics with someone who really likes it if you, yourself, only mildly tolerate it.
I was reading an eighth grade algebra text in order to refresh (for which read: possibly learn for the very first time) the concepts of linear functions. I'll be discussing those with my mento on Monday, so it would be helpful to know them. Or at least have a passing familiarity. I came across a statement which said that you only need two points in order to draw a straight line. Fine, I accept that. Then, about ten sentences later, I came across one that said 'use three ordered pairs and draw a straight line'. It immediately followed that with the parenthetical observation that you really only needed two; the third was a check to see that your line was created correctly -- if all three points were on the same line, you're golden.
Badly written, I told my wife. If they want me to use three, say so up front. Well, they don't, she replied. You only need two. The third is because you might have made a mistake; if all three are on the same straight line, you know you didn't. Then say that up front, I said. Say 'use three pairs -- two to establish the line, and at least one more to verify the line.' But math only needs two, she told me, and that's what they said. I shook my head. No, they didn't. They made a declarative statement that two points are needed; then they made a declarative statement that three points are needed -- and immediately modified that to say well, not really..... but it's a good idea. That modification should be made the first time the definition is given -- and if it wouldn't make sense at that time, then at least make a note to the effect that this isn't precisely right, but it's good enough for now -- we'll tighten the definition later. But they didn't do that. How's a kid supposed to know which declarative statement to believe?
Math aficionados and word aficionados should not discuss math. I guess it works the other way, too, but heck, everyone likes words, right?
No comments:
Post a Comment