Q32 of 78 Page 944

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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