3. Determine if the points (1, 5), (2, 3) and (– 2, – 11) are collinear.
Let the points (1, 5), (2, 3) and (– 2, – 11) be representing the vertices A, B, and C of the given triangle respectively.
Therefore,
Since these are not satisfied.
As these cases are not satisfied.
Hence the points are not collinear.