a. Plot the points $A(6,1), B(3,4),$ and $C(1,-3)$ and their images $A^{\prime}$ $B^{\prime},$ and $C^{\prime}$ under the transformation $R:(x, y) \rightarrow(-x, y)$
b. Prove that $R$ is an isometry. (Hint: Let $P\left(x_{1}, y_{1}\right)$ and $Q\left(x_{2}, y_{2}\right)$ be any two points. Find $P^{\prime}$ and $Q^{\prime},$ and use the distance formula to show that $\left.P Q=P^{\prime} Q^{\prime} .\right)$