Question

how to write the rule for #11 if no rule describe the transformation in words.

Answer 1

Explanation

Let's assume that we have points of the form (x,y). If those points are reflected about the line x=a then the reflected points are given by:

$(a-(x-a),y)=(2a-x,y)$

So for example if we have the points D=(1,1) and E=(0,-2) and we reflect them about the line x=2 we get:

$\begin{gathered} D=(1,1)\rightarrow D^{\prime}=(2-(1-2),1)=(2-(-1),1)=(3,1) \\ E=(0,-2)\rightarrow E^{\prime}=(2-(0-2),-2)=(4,-2) \end{gathered}$

These points D' and E' are the same as those in the graph.

Answer

So the transformation performed in question 11 is a reflection about the line x=2 and it is described with this rule:

$(x,y)\rightarrow(4-x,y)$