What does a reflection across the x or y axis result in?

When a figure reflects across the x-axis or y-axis, it effectively "flips" the figure over that axis. For example, reflecting a point located at (x, y) across the x-axis results in the point (x, -y), while reflecting it across the y-axis gives (−x, y). This transformation preserves the shape and size of the figure but alters its position, effectively causing it to visually flip or mirror over the designated axis.

This phenomenon can be visualized by considering how the vertical or horizontal line acts as a mirror. The points that are on one side of the axis are moved to the opposite side but at the same distance from it, maintaining the integrity and proportions of the original figure. Thus, it is accurately described as a flip.

The other transformations mentioned, such as a slide (translation), rotation around a point, or change in size (dilation), do not accurately characterize the nature of a reflection. Each of those involves different types of movements or alterations to the original figure, but a reflection specifically results in a reversal over the axis.