Question

Fine the coordinates of the vertices of each figure after the given transformation Reflection across y=2 J(1,3) U(0,5) R(1,5) C(3,2)

Answer 1

Recall that a reflection over a line y=k transforms the point (a,b) into the point (a,2y-b), therefore:

$\begin{gathered} J^{\prime}(1,2\cdot2-3)=J^{\prime}(1,4-3)=J^{\prime}(1,1)\text{.} \\ U^{\prime}(0,2\cdot2-5)=U^{\prime}(0,4-5)=U^{\prime}(0,-1)\text{.} \\ R^{\prime}(1,2\cdot2-5)=R^{\prime}(1,4-5)=R^{\prime}(1,-1)\text{.} \\ C^{\prime}(3,2\cdot2-2)=C^{\prime}(3,4-2)=C^{\prime}(3,2)\text{.} \end{gathered}$

Answer: J'(1,1), U'(0,-1), R'(1,-1), C'(3,2).