Find the direction ratios and direction cosines of a line joining the points `(3,-4,6)` and `(5,2,5)`.

Explanation

Direction ratios of the line joining the points `A(3,-4,6)` and `B(5,2,5)`
`a = x^(2)-x_(1), b = y_(2) - y_(1), c = z_(2) - z_(1)`
`a = 5 - 3 , b = 2 + 4 , c = 5 - 6`
`rArr a = 2, b = 6, c = - 1`.
Now, `AB = sqrt(2^(2) + 6^(2) + (-1)^(2)) = sqrt(41)`
`:.` Direction cosines of line `= (2)/(sqrt(41)), (6)/(sqrt(41)), (-1)/(sqrt(41))`.