Mapping Rule anyone?

[no1atall]

Hello everyone,

I have been working as a math tutor for about a year in the Toronto area. I have a background in Electrical Engineering, however I completed most of my studies (high school and collage) within the states. Since moving here and starting this tutoring job, I have come across a concept commonly known here as the "Mapping Rule" time and time again. To me, this concept was pretty foreign, and to I tried to do some research on it, but came up mostly empty. The only references to the "Mapping Rule" I was able to find were from notes my students took in class, and those were very vague and confusing. I tried everything I could think of including asking old friends from collage, and even some international students if they had either heard of this concept before or if they could make sense of it. Long story short I, nor anyone I asked, was able to make sense of the concept. A typical "Mapping Rule" question is something like:

"Given the equation y = -2log(2x-5) + 3, state the state the mapping rule and graph the equation using your key points"

I think I finally had a break through in understanding the question, and answer, and how they arrived at it, but here is my question. Has anyone else heard of this "Mapping Rule," or does anyone understand it enough to be able to explain it. It took me a painstaking year to do this, so am I just stupid, or is this something which is foreign to most?

I appreciate your input on this topic. I will post what the "mapping rule" for the equation is, with an explanation as to how to get to it, once I get some feedback.

Appreciate your time.
~no1atall

 

[pka]

I have been working as a math tutor for about a year in the Toronto area. I have a background in Electrical Engineering, however I completed most of my studies (high school and collage) within the states. Since moving here and starting this tutoring job, I have come across a concept commonly known here as the "Mapping Rule" time and time again. To me, this concept was pretty foreign, and to I tried to do some research on it, but came up mostly empty. The only references to the "Mapping Rule" I was able to find were from notes my students took in class, and those were very vague and confusing. I tried everything I could think of including asking old friends from collage, and even some international students if they had either heard of this concept before or if they could make sense of it. Long story short I, nor anyone I asked, was able to make sense of the concept. A typical "Mapping Rule" question is something like:

"Given the equation y = -2log(2x-5) + 3, state the state the mapping rule and graph the equation using your key points"

If I were you, I would seek out someone in the mathematics education community there and ask.

This is strictly a guess: Often the word map is used in place of the word function.
As in \(\displaystyle f(x)=-2\log(2x-5)+3\) maps \(\displaystyle (2.5,\infty)\to\mathbb{R}\).
Thus \(\displaystyle y=f(x)\)

Any function is a set of ordered pairs: \(\displaystyle f=\{(x,f(x)) : x\in (2.5,\infty)\}\) .
So \(\displaystyle (3,3)\in f\) because \(\displaystyle f(3)=3\).
That is the given rule for \(\displaystyle f(x)\).

Again, that only a guess.