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

Explanation

The given points are `A( 1,2,−3 )and B( −1,−2,1 )`.


Formula for vector equation when initial and terminal points are given is,


`AB → =( x 2 − x 1 ) i ^ +( y 2 − y 1 ) j ^ +( z 2 − z 1 ) k ^`


`Here, x 1 =1, x 2 =−1, y 1 =2, y 2 =−2, z 1 =−3 and z 2 =1`.


...