Question

A circle is graphed on a coordinate grid and then reflected across the y-axis. If the center of the original circle was located at (x, y), which ordered pair represents the center of the new circle after the transformation?

A) (x, y)
B) (x, −y)
C) (−x, y)
D) (−x, −y)

Answer 1

The answer is D) (-X , -y )

Answer 2

This one is pretty easy. You don't even need to write the circles. To figure this one out, draw a graph and plot a point in the first quadrant. This is where x and y are both positive. Then reflect the point across the y- axis. It should look like the picture I drew. Now ask yourself, "Are the x and y positive, or negative? Which one is positive, and which one is negative?"

Answer:

Since the reflected point is in the 2nd quadrant. The x is negative and the y is positive, so it looks like:

(-x, y)