What is the standard definitions of the following transforms? I got them from a practice test for the NY Regents. The test does not include those definitions in its reference sheet.

- $\displaystyle T_{1,-1}$
- $\displaystyle D_2$

I need this for the following:

Triangle ABC has vertices A(5,1), B(1,4), and C(1,1). What are the coordinates of triangle A''B''C'', the image of triangle ABC following composite transformation $\displaystyle T_{1,-1} \circ D_2$.

Answer: A''(11,1), B''(3,7), and C''(3,1).

Thanks.