titik p (6√2,10√2) diputar dengan arah berlawanan jarum jam sejauh 45• menghasilkan p' koordinat p' adalah

jawab

P(x,y) = ( 6√2 , 10√2)
Rotasi 45° berlawanan jarum jam

[tex] \left[\begin{array}{ccc}x'\\y'\end{array}\right]\,=\, \left[\begin{array}{ccc}cos\,45&-\,sin\,45\\sin\,45&cos\,45\end{array}\right]\, \left[\begin{array}{ccc}x\\y\end{array}\right] [/tex]

[tex]\left[\begin{array}{ccc}x'\\y'\end{array}\right]\,=\, \left[\begin{array}{ccc} \frac{1}{2} \sqrt{2}&-\frac{1}{2} \sqrt{2}\\\frac{1}{2} \sqrt{2}&\frac{1}{2} \sqrt{2}\end{array}\right]\, \left[\begin{array}{ccc}6 \sqrt{2}\\10\sqrt{2}\end{array}\right] [/tex]


[tex]\left[\begin{array}{ccc}x'\\y'\end{array}\right]\,=\, \left[\begin{array}{ccc}-4\\16\end{array}\right] [/tex]