Find the direction cosines of the vector joining the points `A(1,2,−3)` and `B(−1,−2,3)` directed from `A` to `B`.

Answer

d

Explanation

The distance of point `(1+3r, 2-r, 3+4r)` from the plane is `(|1+3r+2-r-3-4r-1|)/(sqrt(1+1+1))= (|2r+1|)/(sqrt3)= (4)/(sqrt3)`
`rArr " "r= (3)/(2), -(5)/(2)`
Hence, the points are `A((11)/(2), (1)/(2), (10)/(2)) and B ((-13)/(2), (9)/(2), (-14)/(2))`
`rArr" "AB= sqrt(292)`