Give the equations to find the magnitude and direction of the resultant vector of two vectors $\vec{A}$ and $\vec{B}$ that are inclined at an angle $\theta$ to each other.

• A
  Magnitude: $R = \sqrt{A^2 + B^2 + 2AB \cos \theta}$,Direction: $\tan \alpha = \frac{B \sin \theta}{A + B \cos \theta}$
• B
  Magnitude: $R = \sqrt{A^2 + B^2 - 2AB \cos \theta}$,Direction: $\tan \alpha = \frac{B \sin \theta}{A - B \cos \theta}$
• C
  Magnitude: $R = A + B$,Direction: $\alpha = 0$
• D
  Magnitude: $R = \sqrt{A^2 + B^2}$,Direction: $\tan \alpha = \frac{B}{A}$