(Q15) Verify whether the following points are collinear or not.

(1,-1) , (2,3) , (2,0)

Given : Points are (1,-1) , (2,3) , (2,0)

∆ =
1
2
 |x1(y2 - y3)+x2(y3 - y1)+x3(y1 - y2)|

Area of the triangle formed by the given points are,

  =
1
2
 |1(-)+2(+)+2(--)|
  =
1
2
 |-|
  =
2
 ≠ 0

 ∆ ≠ 0

Hence the points are not collinear.