Question

In each of the following find the value of 'k', for which the points are collinear.

(8, 1), (k, -4), (2, -5)

Answer 1

For collinear points, area of triangle formed by them is zero.

Therefore, for points (8, 1), (k, - 4), and (2, - 5), area = 0

`1/2 [8 { -4- (-5)} + k{(-5)-(1)} + 2{1 -(-4)}] = 0`

8 - 6k + 10 = 0

6k = 18

k = 3