Question

The angular separation between the vectors A = 4i + 3j + 5k and B = i – 2j + 2k is (in degrees)

(a) 65.8

(b) 66.8

(c) 67.8

(d) 68.8

I got this question during an interview.

The question is from Cartesian Coordinate System in division Coordinate Systems and Transforms of Electromagnetic Theory

Answer 1

Right answer is (c) 67.8

For explanation I would say: The dot product the vector is 8. Angle of separation is cos θ = 8/ (7.07 X 3) = 0.377 and θ = cos^-1(0.377) = 67.8.