Problem
Question 1 of 5 Type the correct answer in the box. Trlangle $\mathrm{QRS}$ is reflected across the $y$-axis to create trlangle $\mathrm{Q}^{\prime} \mathrm{R}^{\prime} \mathrm{S}^{\prime}$. Complete the rule that describes the coordinates of triangle $Q^{\prime} R^{\prime} S^{\prime}$ after the reflection has occurred.
Solution
Step 1 ：Triangle QRS is reflected across the y-axis to create triangle Q'R'S'.
Step 2 ：The rule that describes the coordinates of triangle Q'R'S' after the reflection across the y-axis is \((x, y) \rightarrow (-x, y)\).
