Question

Nancy has to find the coordinates of the reflection of a point across the y-axis. How can she find the coordinates of the new point without graphing the point? Is there a rule that she can apply to find it?

Answer 1

Yes, to find the reflection of a point across the y-axis, you can negate the x-coordinate while keeping the y-coordinate unchanged. This rule can be applied to any point (x, y), resulting in the reflected point at (-x, y).

Answer 2

multiply the x coordinate by -1

Explanation:

A and C for example, start with C which is (2, 4), and now to find A, multiply the x coordinate by -1.

2 * -1 = -2

The coordinate of A is (-2, 4)

This works both ways. Get L to G. L is (-4, -2) and G is (4, -2)

Multiply the L's x coordinate by -1 and you get -4 * -1 = 4

The y coordinate stays the same if it is a reflection across the y-axis. This can also be flipped and used for finding reflections across the x-axis using the same rules.