If a vector K has component Kx = 4.1 and Ky = -13, then find the magnitude K and direction (as a positive rotation angle relative to the +x axis) of the vector.

Question

If a vector K has component Kx  = 4.1 and Ky = -13, then find the magnitude K and direction (as a positive rotation angle relative to the +x axis) of the vector.

bobpursley · Answer

Kmag=sqrt(4.1^2 +(-13)^2)

I don't have a clue what "positive" rotation means. If you mean clockwise as positive, then
Theta=arctan13/4.1
If you mean counterclockwise rotation as "positive", then
theta= 360deg - aboveangle