Hi Candidate,

The Cartesian coordinate system is used for measuring the coordinates in the 3- Dimensional Catersian Plane with respect to the Origin.

In the given Question, the coordinates of A are given as (1,2,3) and the coordinates of C are given as (2,2,4) with the origin having coordinates (0,0,0). So the CA bar has coordinates= (2-1, 2-2, 4-3)= (1,0,1).

Hope that this answer helps you.