A(2,4) B(0,-2), C(1,1)
Conditia de coliniaritate este ca determinantul acesta sa fie 0.
[tex]\left|\begin{array}{ccc} x_{A} &y_{A} &1\\x_{B} &y_{B} &1\\x_{C} &y_{C} &1\end{array}\right|=0 \\ \\ \\ \left|\begin{array}{ccc} 2 &4 &1\\0 &-2 &1\\1 &1 &1\end{array}\right|=0 \\ \\ -4+0+4+2-2+0 = 0 \\ 0=0[/tex]
=> A,B,C coliniare.
