Question

answer the question​

Answer 1

Answer:

Let angle between both vectors x , use formula of resultant

$r = \sqrt{3} = \sqrt{ {1}^{2} + {1}^{2} + 2(1)(1) \cos(x) } \\ 3 = 2 + 2 \cos(x) \\ \cos(x) = \frac{1}{2} \\ \\ x = \frac{\pi}{6}$

Now

(A1 + A2).(2A1 - A2)

= 2(A1.A1) -A2.A1 + 2(A2.A1)-A2.A2

= 2 - Cos x + 2Cos x - 1

= 1 - Cos x

= 1 - 1/2

= 1/2