Find the value of k for which the point A (– 1, 3), B (2, k) and C (5, – 1) are collinear.
Three points A, B and C are collinear if and only if
Area(ΔABC) = 0
As we know area of triangle formed by three points (x1, y1), (x2,y2) and (x3, y3)
⇒ 0= – 6k + 6
⇒ 6k = 6
⇒ k = 1
So, For k = 1, A, B and C are collinear.
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