If two forces of equal magnitude 4 units acting at a point and the angle between them is `120^(@)`, then find the magnitude of direction of the sum of the two vectors

Options

A. `4, theta=tan^(-10(1.73)`
B. `4, theta=tan^(-1)(0.73)`
C. `2, theta=tan^(-1)(1.73)`
D. `6, theta^(-1)(0.73)`

Explanation

(a) `|R|=|a+b|=sqrt(4^(2)+4^(2)+2(4)cos 120^(@))`
`|R|=4`
Let `theta=` angle between `a+b` with `x`-axis
`theta=tan^(-1)((4sin (120^(@)))/(4+4cos(120^(@))))="tan"^(-1)(3.646)/2=tan^(-1)(1.73)`