Question

Two vectors A and are added as shown in figure. If
angle between A and B is $, then angle between A and
resultant vector R is
B*
R=A+8
G​

Answer 1

Answer:

angle α which the resultant R makes with A is given by

tanα=

A+Bcosθ

Bsinθ

or

cos(θ/2)

sin(θ/2)

=

A+Bcosθ

2Bsin(θ/2)cos(θ/2)

which gives A+Bcosθ=2Bcos

2

(

2

θ

)

or A+B[2cos

2

(

2

θ

)−1]=2Bcos

2

(

2

θ

)

A=B