# Vector and the + x axis

## Homework Statement

So I have been doing the adding of vectors by using their components and you are suppose to use the + X axis as a reference frame so when 3 vectors are given do you always have to subtract the given theta from the quardrant total ie. 22m, 56 degrees west of south plotting this places the vector with in the 3rd quadrant so you would have to do 270-56 in order to get the degree used in the vx= v cos theta or vy= vsin theta. but I have seen other problems where the vector resides in the 3rd quadrant and the solution is achieved by using the theta stated in the problem and you do not have to subtract it from the 270. So i am confused about the rules of the is process can someone please explain

vx= v cos theta
vy= v sin theta