Question

The vector A and B are such that |A + B| = | A - B| then the angle between the two vector A and B will be:
(A) 0° (C) 90°
(B) 60° (D) 180°

Answer 1

For the angle between a and b we have to these values….. Because

cosθ= $a⋅b/ |a||b|$

Given. | a+b| = | a- b|

| a+b|² = | a- b|²

a² + b² + 2ab = a² + b² - 2ab

………….. 4ab = 0

So…….. a.b = 0

Put the value in that equation……

cosθ = $0/ |a||b|$

cosθ= cos90°

So the angle between a and b is 90° or π/ 2