Răspunsuri

2014-02-03T19:04:46+02:00
Conditia de coliniaritate este  \frac{x_{2} -  x_{1}}{x_{3} -  x_{1}} = \frac{y_{2} -  y_{1}}{y_{3} -  y_{1}}

 \frac{-2 - (-4)}{-3-(-4)} =  \frac{-6-2}{-2-2}

Deci avem  \frac{-2+4}{-3+4}= \frac{-6-2}{-2-2}

 \frac{2}{1} =  \frac{-8}{-4}

2 = 2 Adevarat deci A, B, D sunt coliniare.
2014-02-03T19:57:50+02:00
Vectorii AB si BD sunt coliniari: xB-xA / xD-xB=yB-yA/yD-yB
sau 
regula triunghiului, paralelogramului