It's pretty easy tan(-a)= -tan a
So, Tan(-45) = -1
Now tan is negative in the 2nd and 4rth quadrant.
So tan(180-45)= -1, tan(360-45)=-1,tan(540-45)=-1 It has Infinite solutions.
Could be a=135,315 etc.
I'll agree with Luke.Current will flow from A to B but the Negative charge will flow from B-A as negative charges move from lower potential to Higher potential.
For example.Think of a Circuit normally the current flows from higher potential to lower potential (Positive Terminal to Negative...