1. Write down the 4 × 4 3D matrix to move by (xm, ym, zm).
2. Write down the 4 × 4 3D matrix to rotate by an angle ? about the y-axis.
3. Write down the 4 × 4 3D matrix to scale an object by 50% in all directions.
4. Write the 2D rotation matrix that rotates by 90 degrees clockwise.
5. Write the matrix from Exercise 4 as a product of three shear matrices.
6. Find the inverse of the rigid body transformation:
where R is a 3 × 3 rotation matrix and t is a 3-vector.