Question

Find the coordinates of M' after a reflection across the line y= -1 and then across the x=-2.

Answer 1

Answer:

  M' = (-1, 3)

Step-by-step explanation:

The two reflections are equivalent to a reflection across the point P = (-2, -1), which becomes the midpoint of the line segment MM'. The coordinates of M' can be found from ...

  M' = 2P -M = 2(-2, -1) -(-3, -5) = (-4+3, -2+5)

  M' = (-1, 3)

_____

The formula used comes from the formula for the midpoint:

  P = (M +M')/2

  2P = M + M' . . . . multiply by 2

  M' = 2P - M . . . . .subtract M