Question

Show that the following points are collinear:

A(8, 1), B(3, –4) and C(2, –5)

Answer 1

`"Let" A(x_1=8,y_1=1), B (x_2=3, y_2=-4) and C (x_3 = 2, y_3=-5) ` be the given points.

Now `x_1(y_2-y_3)+x_2(y_3-y_1)+x_3(y_1-y_2)`

=8 (-4+5) +3 (-5-1) +2(1+4)

= 8 - 18 + 10

=0

Hence, the given points are collinear.