Question

If ã and b are two unit vectors such that ā +25 and 5ā - 45 are perpendicular to each other
then the angle between ã and 5 is. Find value of n.

Answer 1

Explanation:

∣a−b∣

2

=(a−b).(a−b)=∣a∣

2

∣b∣

2

−2∣a∣∣b∣cosϕ

=2(1−cosϕ)=4sin

2

(

2

ϕ

)

Hence (

2

1

)∣a−b∣=

∣

∣

∣

∣

∣

sin

2

ϕ

∣

∣

∣

∣

∣

hope it helps you plz make me brincly