Question

32. The vectors à and b are such that lã+b] =
a - bl. What is the angle between ã and b?
a)0° b)90°C) 60° d)180°​

Answer 1

Answer:

b) 90°

Explanation:

This is b'cuz

|ā+b|=(a^2 +b^2+ 2abcosø)^1/2--[1]

|ā-b|=(a^2+ b^2- 2abcosø)^1/2--(2)

Now eqn. 1= eqn. 2 only if cos ø =0

=> ø = 90°