REFLECTION MATRIX

Definition of Reflection Matrix

A matrix that is used to reflect an object over a line or plane is called a reflection matrix.

Examples of Reflection Matrix

  • The figure below shows the reflection of triangle ABC about the y-axis.
  • is the reflection matrix for the y-axis.
      Examples of Reflection Matrix

Video Examples: Reflection Matrix


Solved Example on Reflection Matrix

Ques: Find the coordinates of the vertices of the ../image_md of triangle ABC with A(1, 3), B(-1, 1), C(3, 1) after a reflection across the y-axis.

    Choices:
    A. A'(- 1, 3), B'(1, 1), C'(- 3, 1)
    B. A'(- 1, - 3), B'(1, 1), C'(- 3, 1)
    C. A'(- 1, 3), B'(1, - 1), C'(- 3, 1)
    D. A'(- 1, 3), B'(1, 1), C'(3, 1)

Solution:

    Step 1: The coordinates of the vertices of triangle ABC are given by A(1, 3), B(-1, 1), C(3, 1)
    Step 2: Then multiply the vertex matrix by reflection matrix for the y-axis

    Examples of Reflection Matrix
    Step 3: Therefore, the coordinates of the vertices of A'B'C' are A'(- 1, 3), B'(1, 1), C'(- 3, 1).