Similarly, direction cosines of y-axis and z-axis are 0, 1, 0 and 0, 0, 1 respectively Example 5 Show that the points A (2, 3, – 4), B (1, – 2, 3) and C (3, 8, – 11) are
collinear Solution Direction ratios of line joining A and B are
1 – 2, – 2 – 3, 3 + 4 i e