Given : A line has direction ratios 2, -1, -2

To find : Direction cosines of the line

Formula used : If (l,m,n) are the direction ratios of a given line then direction cosines are given by , ,

Here l = 2 , m = -1 , n = -2

Direction cosines of the line with direction ratios 2, -1, -2 is

, ,

= , , = , ,

= , ,

Direction cosines of the line with direction ratios 2, -1, -2 is , ,