bayangan titik R(-4,4)yang dirotasikan(0,-45derajat)

Matriks transformasi untuk rotasi -45° terhadap O (titik pusat adalah):
[tex]T= \left[\begin{array}{cc}\cos(-45)^\circ&-\sin(-45)^\circ \\ \sin(-45)^\circ&\cos(-45)^\circ\end{array}\right]=\left[\begin{array}{cc}\frac12\sqrt2&\frac12\sqrt2 \\ -\frac12\sqrt2&\frac12\sqrt2\end{array}\right][/tex]

Maka bayangan titik R adalah:
[tex]R'=TR \\ R'=\left[\begin{array}{cc}\frac12\sqrt2&\frac12\sqrt2 \\ -\frac12\sqrt2&\frac12\sqrt2\end{array}\right]\left[\begin{array}{c}-4 \\ 4\end{array}\right] \\ R'=\left[\begin{array}{c}-2\sqrt2+2\sqrt2 \\ 2\sqrt2+2\sqrt2\end{array}\right] \\ R'=\left[\begin{array}{c}0 \\ 4\sqrt2\end{array}\right][/tex]

Bayangan titik R adalah (0,4√2)