\(= (T_2 . T_1) \begin{pmatrix} x \\ y \end{pmatrix} \)
Artinya titik (x,y) ditransformasikan oleh T_1 dilanjutkan T_2
\(= \begin{pmatrix} k & 0 \\ 0 & k \end{pmatrix} \begin{pmatrix} x-a \\ y-b \end{pmatrix} + \begin{pmatrix} a \\ b \end{pmatrix}\)
\(= \begin{pmatrix} k & 0 \\ 0 & k \end{pmatrix} \begin{pmatrix} x \\ y \end{pmatrix}\)
\(= \begin{pmatrix} \cos\theta & -\sin\theta \\ \sin\theta & cos\theta \end{pmatrix} \begin{pmatrix} x-a \\ y-b \end{pmatrix} + \begin{pmatrix} a \\ b \end{pmatrix}\)
dimana
\(x' = (x-a) \cos \theta - (y-b) \sin \theta + a
\\y' = (x-a) \sin \theta + (y-b) \cos \theta + b
\)
\(= \begin{pmatrix} \cos\theta & -\sin\theta \\ \sin\theta & cos\theta \end{pmatrix} \begin{pmatrix} x \\ y \end{pmatrix}\)
dimana
\(x'= x\cos \theta - y \sin \theta \\y' = x \sin \theta + y \cos \theta\)