Apply geometric motions to reflect figures. Brinda reflects point T(2, 3)

over a line of reflection, resulting in point T′(2, −5)
. What must be true?(1 point)
Responses

The line of reflection is x=−1
.
The line of reflection is x is equal to negative 1 .

The line of reflection is the x-axis.
The line of reflection is the x -axis.

The line of reflection is y=−1
.
The line of reflection is y is equal to negative 1 .

The line of reflection is the y-axis.

1 answer

To find the line of reflection that maps point T(2, 3) to point T′(2, −5), we can use the property that the line of reflection is the perpendicular bisector of the segment connecting the original point and its image.

  1. First, we find the midpoint of segment TT′:

    • Midpoint \( M \) of segment \( TT′ \) can be calculated as: \[ M = \left( \frac{x_1 + x_2}{2}, \frac{y_1 + y_2}{2} \right) = \left( \frac{2 + 2}{2}, \frac{3 + (-5)}{2} \right) = \left( 2, \frac{3 - 5}{2} \right) = \left( 2, -1 \right) \]
  2. Next, we determine the slope of the segment \( TT′ \):

    • The slope \( m \) is given by: \[ m = \frac{y_2 - y_1}{x_2 - x_1} = \frac{-5 - 3}{2 - 2} = \frac{-8}{0} \] This indicates that the segment is vertical, as the change in x is 0.
  3. The line of reflection will be a horizontal line that passes through the midpoint. Since the midpoint is \( M(2, -1) \), the line of reflection is the line \( y = -1 \).

Thus, the correct response is: The line of reflection is \( y = -1 \).