Q18 of 50 Page 220

Show that the three points A (2, 3, 4), B (–1, 2, – 3) and C (– 4, 1, – 10) are collinear and find the ratio in which C divides AB.

Given; Three points A (2, 3, 4), B (–1, 2, – 3) and C (– 4, 1, – 10)



=√59




=√59




=√236


=2√59


⇒ AB + BC = AC; Points A, B and C are collinear.


AC: BC = 2√59:√59 = 2:1


∴ from the lengths of AB, BC and AC we can say that C divides AB in the ratio 2:1 externally.


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