Question

write the condition of collinearity of point (x1, y1) (x2, Y2) (x3, y3)

Answer 1

[ X1 ( y2-y3) + X2 ( y3-y1) + X3 ( y1-y2) ] = 0

Answer 2

Answer:

Prove that (x1, y1), (x2, y2) , and (x3, y3) are collinear points if and only if

[x1 y1 1, x2 y2 1, x3 y3 1] = 0