Aunit cell has a lattice constant a, where a is the length of a single side of the unit cell. draw a cube and derive the length of the diagonal from one top corner of the unit cell to the bottom far corner (ie. the largest distance between corners in a 3-d cube)

Along wire carrying a 4.2 a current perpendicular to the xy-plane intersects the x-axis at x=−1.7cm. a second, parallel wire carrying a 3.0 a current intersects the x-axis at x=+1.7cm. part a at what point on the x-axis is the magnetic field zero if the two currents are in the same direction? express your answer to two significant figures and include the appropriate units.