Question

If be are three unit vectors such that
a+b+c=0 then & biberea is equal to​

Answer 1

Answer

.-3/2

Explanation.

a+b+c=0

implies

a.(a+b+c)=0

a.b+a.c=-1(since magnitude of a is 1)

Similarly

b.c+a.c=-1

a.b+b.c=-1

Adding above equayions, we get

2(a.b+b.c+c.a)=-3

therefore

a.b+b.c+c.a=-3/2.