Question

Three vectors which are coplanar with respect to a certain rectangular co-ordinate system are given by `a = 4 hati - hatj, b = - 3hati + 2hatj and c =- 3hatj`
Find
(a) `a+b+c`
(b) `a+b+-c`
(c ) Find the angle between `a+b+c and a+b-c`

Answer 1

Correct Answer - A::B::C
(a) `a+ b +c = p =I - 2hatj`
(b) `a + b - c = hati+ 4hatj =Q`
(c ) Angle Between `P` and `Q` is `theta = cos^(-1) ((P.Q)/(PQ)`