Point DD is located at left parenthesis, 2, comma, 1, right parenthesis(2,1) on the coordinate plane. Point DD is reflected over the yy-axis to create point D, primeD


. Point D, primeD

is then reflected over the xx-axis to create point D, start superscript, prime, prime, end superscriptD
′′
. What ordered pair describes the location of D, start superscript, prime, prime, end superscript, question markD
′′
?

1 answer

To find the location of point \( D'' \) after reflecting point \( D \) twice, we can follow these steps:

  1. Start with point \( D = (2, 1) \).

  2. Reflect over the y-axis: When reflecting a point \( (x, y) \) over the y-axis, the x-coordinate changes sign, while the y-coordinate remains the same. Therefore, reflecting \( D(2, 1) \) over the y-axis gives us: \[ D' = (-2, 1) \]

  3. Reflect over the x-axis: Next, we reflect point \( D' \) over the x-axis. When reflecting a point \( (x, y) \) over the x-axis, the y-coordinate changes sign, while the x-coordinate remains the same. Therefore, reflecting \( D'(-2, 1) \) over the x-axis gives us: \[ D'' = (-2, -1) \]

So the ordered pair that describes the location of \( D'' \) is: \[ \boxed{(-2, -1)} \]