The points (7, –2), (5, 1), (3, k) are collinear if the area of the triangle formed by the points will be zero.
Area of the triangle is given by:
Substituting the values in the above equation, we obtain
Hence, the points are collinear for k=4.
2.(i) In each of the following find the value of ‘k’, for which the points are collinear. (7, –2), (5, 1), (3, k)