Let a, b, c R be such that a^2+b^2+c^2=1. If a =b ( + 2 3 )=c ( + 4 3 ), where = 9 , then the angle between...

Question

Let a, b, c R be such that a^2+b^2+c^2=1. If a =b ( + 2 3 )=c ( + 4 3 ), where = 9 , then the angle between the vectors a i +b j +c k and b i +c j +a k is -

Accepted Answer

(A)

JEE Main 2020 Mathematics question

Solution