diketahui matriks A =[tex] \left[\begin{array}{ccc}6&-2\\-6&5\\\end{array}\right] [/tex] jika matriks ( A-kl) adalah matriks singular, nilai k adalah

Singular artinya Determinannya jadi 0
[tex] \left[\begin{array}{cc}6&-2\\-6&5\end{array}\right] +k \left[\begin{array}{cc}1&0\\0&1\end{array}\right]= \left[\begin{array}{cc}6&-2\\-6&5\end{array}\right]+ \left[\begin{array}{cc}k&0\\0&k\end{array}\right] \\ \\ \left|\begin{array}{cc}6+k&-2\\-6&5+k\end{array}\right| =0 \\ \\ (6+k)(5+k)-(-6)(-2)=0 \\ 30+11k+k^2-12=0 \\ k^2+11k+18=0 \\ (k+9)(k+2)=0 \\ k=-9$ dan $k=-2[/tex]