Calculating Sums Of Maths

Question

Slightly confused. Would I be correct in saying to find the direction angle of the resultant, I would need to do $\tan^{-1}(\frac y x)$?

Answer 1

Yes that's correct if we are using an orientation for the angle otherwise we can simply evaluate the angle between the resultant and the $x$ component as

$$\theta=\arctan\left(\frac{|-5.55|}{|16,4|}\right)=18.7°$$