Find the coordinatesof the vertices of each figure after the

Find the coordinatesof the vertices of each figure after the given transformation.

12) reflection across y=2

J(1,3), U(0,5), R(1,5), C(3,2)

Solution

To reflect across y = 2, we need all these points reflections to have same x co ordinate but their y co ordinates must be on the other side of the line y = 2 and equally far from it.

Suppose I have (4, 5) as a point, which is 3 units above y = 2, which needs to become (4, 0) which is 2 units below y = 2.

So we will do this by (4, 2 + (2 - 4))

For J (1, 3) we get new point as,

J\' (1, 2 + (2 - 3)) = j\' (1, 2 - 1) = j\'(1, 1)

This finds the distance from the point to y = 2 by subtracting the point\'s y co ordinate from 2, then moves the point that far to the other side of y = 2 by adding 2.

Similarly you can do for rest of the points and plot those points to check whether the graph is reflected about y = 2.