Question

In the coordinate plane, the points X(−11 4) Y( 10 2) and Z(−3− 5) are reflected over the y-axis to the points X′, Y′, and Z′, respectively. What are the coordinates of X′, Y′, and Z′?

Answer 1

We are given the points X(-11,4), Y(10,2) and Z(-3,-5) and asked to find their reflection over the y-axis. Note that given a point of the form

when we reflect it over the y-axis, we get the red dot

Note that the reflection over the y-axis gives you a point that has the same height. This means that when we reflect over the y-axis, we fix the y coordinate of the point. What changes is the x coordinate. The change is simply obtained by multiplying the x coordinate by -1. So, we get the following table

X(-11,4)--->X'(11,4)

Y(10,2)--->Y'(-10,2)

Z(-3,-5)-->Z'(3,-5)