1. ## Transformation notation question

I taught middle school math and I'm somewhat familiar with transformations, but I have no idea what the notations in this problem mean. I looked in two geometry books with no luck. Google, no luck. Khan Academy, well, you get the idea. I'm tutoring two students who are doing distance learning, and I don't have access to their materials. I don't mind admitting that I don't know something, but I hate to look REALLY stupid.
I meet with them tomorrow.
rsn

2. ## Re: Transformation notation question

looks like $T_{a,b}$ is a translation $a$ units in the $x$-direction and $b$ units in the $y$-direction

and $r_{x=y}$ a reflection across the line $x=y$

3. ## Re: Transformation notation question

Thank you for your helpful and rapid response. I'm attaching my work. I think that I have a proper explanation.

mrmac

4. ## Re: Transformation notation question

Looks good

the inverse of a translation

$$\left(T_{a,b}\right){}^{-1}=T_{-a,-b}$$

the inverse of a reflection

$$r^{-1}=r$$