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Geometric Linear Transformations in 2D space

Geometric Linear Transformations

In this section, we describe some specific linear transformations in that are geometric in nature. They are as follows:
  1. Rotation about the origin through a given angle
  2. Reflection in a line that passes through the origin
  3. Scaling horizontally or vertically
  4. Horizontal or vertical shear
  5. Projection onto x-axis or y-axis
In the applet, you can see the effect on under various geometric transformations: First, you select the type of geometric linear transformation . Second, you click the "Set" button to set up the corresponding and and the matrix for . Then click the "Go" button to see how the triangle is transformed under .

What is the general form of the matrix for the rotation about the origin through angle in the counterclockwise direction?

Find the matrix for the 2D linear transformation that first rotates about the origin through in the counterclockwise direction and then reflect on the y-axis.