Diketahui matriks A = (2 5 1 3), B = (-2 1 -4 5), C = (-7 6 -2 1)

by

det (AB – 2C) =

10
Pembahasan:
AB – 2C = ⎛2 5⎞ ⎛-2 1⎞ _ 2⎛-7 6⎞
                   ⎝1 3⎠ ⎝-4 5⎠      ⎝-2 1⎠
= ⎛-24 27⎞ _ ⎛-14 12⎞
   ⎝-14 16⎠    ⎝-4     2⎠
= ⎛-10 15⎞
   ⎝-10 14⎠
det (AB – 2C) = –10.14 –(–10).15
                        = –140 + 150
                        = 10
  Koordinat titik potong grafik fungsi kuadrat 6x² + x – 2