Reflection of points in the coordinate plane: ACT Math Practice Question

Try the following ACT math practice question that tests your understanding of reflection of points across the vertical axis and straight lines in the coordinate plane.

In the $xy$-coordinate plane, point $A$ is the reflection of the point with coordinates $(4, 2)$ across the straight line $y = x$. If point $B$ is the reflection of point $A$ across the $y$-axis, what are the coordinates of point $B$?

1. $\quad (2, -4)$
2. $\quad (-2,-4)$
3. $\quad (-2, 4)$
4. $\quad (-4, -2)$
5. $\quad (-4,2)$

Choice C

Video Explanation