How is the magnetic field at a point due to a current-carrying wire calculated in 3D? Let's say the wire has a current I placed along the x-axis in the direction of x. Would it just be μ0I/(2π)yʸ+μ0I/(2π)zᶻ? I realized that this doesn't quite make sense as when there's a point at z=0, this would give a magnetic field of infinity. How could I get the magnetic field in this case?