Question

If a and b bar are two vectors such tho |a|= 4, b=1/2 and a.b = -1. -

find the angle between a and b​

Answer 1

Answer:

120°

Explanation:

Cos angle = a.b / |a| |b|

= - 1 / [4 ÷ (1÷2)]

= - 1/ 2

Angle = cos ^ - 1 (-1/2) = 120°