Question

Q#10 If Vectors |A|=|B|= 1 and A.B = 1/2 then |A-B| = ?
(a) 2
(b) 5
(c) 0
(d) 1​

Answer 1

Given,

|A| =|B| = 1

A.B = 1/2

we know,

A.B = ABcos∅ = 1/2

AB = 1 {give)

cos∅ = 1/2

so, ∅ = 60°

Now,

|A-B| = √(A²+(-B)²-2ABcos∅)

=>√(1+1-2×1/2)

=>√(2-1) = 1

The correct option is (d)1

Cheers!