Three Dimensional Geometry Part 1

Let P(x1,y1,z1) and Q(x2,y2,z2) be the initial and final points of the vector whose projections on the three coordinates axes are 6,−3,2 then
x2−x1,=6;y2−y1=−3;z2−z1=2
So that directions ratios of

→

PQ

are 6,−3,2
∴ Direction cosines of

→

PQ

are
‌‌

6

√62+(−3)2+22

,‌

−3

√62+(−3)2+22

‌‌

2

√62+(−3)2+22

=‌

6

7

,‌

−3

7

,‌

2

7