# Vector Potential

Hello all. I am hoping someone could lend a hand. I need to determine the vector potential of a long wire. I am given the B-field = ($$\mu$$I)/(2$$\pi$$r) and I know at some point I will need to use $$\nabla$$ X A. Thanks in advance.

What's the equation of $$\bar{B}$$ in terms of $$\bar{A}$$?