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Question
In each of the following find the value of 'k', for which the points are collinear.
(8, 1), (k, -4), (2, -5)
Solution
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
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