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Matt Enlow Profile picture
Matt Enlow
@CmonMattTHINK
Mathematician • High School #Math Teacher • #HumanizeMath • #ADHD • Thought follower • Bridge builder • People puzzler • Humanizer • @UnsolvedMrE@mathstodon.xyz
Aug 18, 2021 • 5 tweets • 2 min read
This topic flummoxes me every year. I want the Ss to understand WHY a shift 3 to the right is achieved by replacing every x with x-3 (not x+3), rather than just memorize, "It's the opposite."

I'm convinced that we need to start talking about this with relations, not functions. Something like this.

"Here is a relation R. Complicated, huh? Fortunately, I have a computer program that will tell me whether or not a given point is an element of R. I give it an (x,y), and it tells me yes or no. I don't know how it figures it out... but I don't need to!" Image