Question

What is the angle between `vec(P)` and the resultant of `(vec(P)+vec(Q))` and `(vec(P)-vec(Q))` ?
A. zero
B. `tan^(-1)(P//Q)`
C. `tan^(-1)(Q//P)`
D. `tan^(-1)(P-Q)//(P+Q)`

Answer 1

Correct Answer - A
(a) Resultant of `(P+Q) and (P-Q) is P+Q+P-Q or 2P` which is parallel to P.
So, angle between P and 2P will be zero.