Question

if A × B =√3AB find value of A +B​

Answer 1

Answer:

|AB|= 3A.B

|AB| = 3|A |.| B | cos∅ wABhere ∅ is angle between a and b .

|AB| = 3|AB|cos∅

1 = 3cos∅

cos∅ = 1/3 -------(1)

| A + B | = √{A² + B² + 2|A|.|B|.cos∅}

= √{A² + B² + 2|A|.|B|.×1/3 }

when , A and B are unit vectors .

= √{ 1 + 1 + 2 × 1/3 }

= 2√2/3