Question

Find the distance of point p whose position vector is 3i+6j+8k

Answer 1

I’m assuming that by |AB|, you mean the length of the vector difference A-B.

Then:

A - B = (I+2J-3K) - (2I-4J+K) = -I+6J-4K

Next, |A-B| = Sqrt((A-B).(A-B)) = Sqrt(1 + 36 + 16) = Sqrt(53)

Thus |AB| = Sqrt(53) =? 7.2801