Question

The two vector having equal magnitude and the resultant also has the same magnitude then find the angle between the vector

Answer 1

HEY mate here is your answer..

the angle between them 120° .
it can be verified by equilateral triangle,as the resultant and the vectors become an equilateral triangle when connected.

hope this will help you.

Answer 2

Let the resultant = magnitude of vector a=magnitude of vector b=X
Then
X^2= X^2+X^2+X^2costheta
X^2=2X^2+2X^2 cos theta
-X^2=2X^2cos theta
Cos theta=-1/2
Or theta = 120 degree
Hope that helps you :-)