Question

`vec(A)+vec(B)=2hat(i)` and `vec(A)- vec(B)=4hat(j)` then angle between `vec(A)` and `vec(B)` is ?

Answer 1

Correct Answer - `127^(@)`
`vec(A) =hat(i)+2hat(j)and vec(B) =hat(i)-2hat(j)`
`vec(A).vec(B)=|vecA||vec(B)|cos theta, cos theta=(-3)/(5)`
`theta =127^(@)`