Question

Given the initial point x,y. What coordinates expression gives the new coordinate of the point after a reflection across the y-axis?

Answer 1

The new coordinates of a point after a reflection across the y-axis are (-x, y), where the x-coordinate changes sign and the y-coordinate remains unchanged.

Step-by-step explanation:

When a point with coordinates (x, y) is reflected across the y-axis, the x-coordinate changes sign while the y-coordinate remains the same.

Thus, the new coordinates of the point after the reflection are (-x, y).

This process effectively 'mirrors' the point to the opposite side of the y-axis, but at the same distance from it.

The y-axis acts as a line of symmetry for this reflection.