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

C.

Explanation:

First, to see it better, you need to know that the y-axis can be referenced as "up or down" and the x-axis as "left or right".

Now, one ordered pair (x,y) after the reflection across the y-axis will be moved "from left to right" or "from right to left", then the y-value doesn't change and the x-value changes sign (to preserve the distance). Then, the the new center will be (-x,y). So, the answer is C.

Answer 2

Option C. (-x,y)

Explanation:

we know that

A point reflected across the y-axis has the following rule

(a,b)------> (-a,b)

so

If the center of the original circle was located at (x, y)

then

the center of the new circle after the transformation will be (-x,y)