Saturday, August 08, 2009

Obscurity Resolved?

In my recent reading of the Ontario Grade 11 Math curriculum (also known as Grade 11 Functions), I came across numerous references to the following cryptic notation:

y = af(k(x-d))+c

with no real explanation as to what it meant. It's obviously a variation on the typical format of function notation, where f(x) = some operation on x, but there was no indication as to what a, k, d or c represented.

When I initially Googled that particular set of characters, I couldn't find anything useful, and began to despair of ever understanding what the significance was. Then I stumbled across a site describing geometric transformations of functions that, I think, solved the mystery for me. If I'm right, then the function notation above represents the translations, compressions, stretches and reflections that a function can be put through, via the introduction of constants in place of a, k, d and c. None of this is familiar to me from 1979/80 (when I would have originally taken Grade 11 Functions and received a mark somewhere north of 90%, I imagine) but it all makes sense, given what I read at that transformations website.

It's definitely getting harder to familiarize myself with the material required for this Math Tutoring position of mine as I move to the higher grades, but I guess even that has its own appeal, in a way.

1 comment:

Anonymous said...

Let me state this plainly: I think this notation sucks.