Matricies as transformations

• As geometric transformations
• As algebraic transformations

\(\begin{matrix}x &0 \\ 0 &y\end{matrix}\) | Scale by \(x\) and \(y\) \(\begin{matrix}0 &1 \\ -1 & 0\end{matrix}\) | Rotate -90deg (easier to visualize geometrically, also two reflections (over \(y=x\) and \(y=0\))) \(\begin{matrix}1 &1 \\ 0 &1\end{matrix}\) | Add \(y\) to \(x\) (easier to visualize algebraically, also a shear)

• KBe2020math530retPracticeMultiplyMatrixIdentfyGroups