geometric-transformations-with-matrices

2D transformations

What is meant by a 2D geometric transformation?

• The following transformations can be represented (in 2D) using multiplication of a 2×2 matrix

  • rotations (about the origin)

  • reflections

  • enlargements

  • (horizontal) stretches parallel to the x-axis

  • (vertical) stretches parallel to the y-axis

What are the matrices for geometric transformations?

• Rotation

  • Anticlockwise (or counter-clockwise) through angle θ about the origin

    • 

    • This is given in the formula booklet

  • Clockwise through angle θ about the origin

    • 

  • In both cases

    • θ > 0

    • θ may be measured in degrees or radians

• Reflection

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