Question
Show that the points A (2, 6, 3). B (1, 2, 7) and C (3, 10, – 1) are collinear.
Solution
The given points are A (2, 6, 3), B (1, 2, 7) , C (3, 10, –1).
Let O be origin.

But B is their common point
∴ points A, B, C are collinear.
Let O be origin.

But B is their common point
∴ points A, B, C are collinear.