titik A(7,-8) dirotasi sejauh 90° kemudian dilanjutkan oleh translasi T (-3 4) bayangan ahir titik A adalah ...

jawabannya................... (5,11)

jawab

(x,y) = (7,8)
R(O, 90)
T(a,b) = (-3 , 4)

[tex] \left[\begin{array}{ccc}x' \\ y' \end{array}\right]\,= \left[\begin{array}{ccc}cos\,90&-sin\,90\\-sin\,90&cos\,90\end{array}\right] \left[\begin{array}{ccc}x\\ y\end{array}\right]\,+\, \left[\begin{array}{ccc}a\\b \end{array}\right]\,[/tex]

[tex]\left[\begin{array}{ccc}x' \\ y' \end{array}\right]\,= \left[\begin{array}{ccc}0&-1\\1&0\end{array}\right] \left[\begin{array}{ccc}7\\-8 \end{array}\right]\,+\, \left[\begin{array}{ccc}-3\\4\end{array}\right][/tex]

[tex]\left[\begin{array}{ccc}x' \\ y' \end{array}\right]\,= \left[\begin{array}{ccc}8\\7 \end{array}\right]\,+\, \left[\begin{array}{ccc}-3\\4\end{array}\right]\,=\left[\begin{array}{ccc}5\\ 11\end{array}\right] [/tex]