Jawabanmu

2014-06-24T00:07:28+07:00
Pencerminan terhadap sumbu y dilanjutkan rotasi +90°, maka:
  \left[\begin{array}{ccc}0&-1\\1&0\end{array}\right] \left[\begin{array}{ccc}-1&0\\0&-1\end{array}\right] \left[\begin{array}{ccc}x\\y\end{array}\right] = \left[\begin{array}{ccc}x"\\y"\end{array}\right]

\left[\begin{array}{ccc}0&-1\\-1&0\end{array}\right] \left[\begin{array}{ccc}x\\y\end{array}\right] = \left[\begin{array}{ccc}x"\\y"\end{array}\right]

\left[\begin{array}{ccc}-y\\-x\end{array}\right] = \left[\begin{array}{ccc}x"\\y"\end{array}\right]

karena -y = x", dan -x = y", subtitusikan ini ke persamaan awal menjadi:

= x- 2y + 4
= -y" + 2x" +4
= 2x" - y" + 4
atau bisa juga ditulis 2x - y + 4

semoga membantu!