Answer:
field B = µ₀c I / 2πr
The field in the xy plane due to the fact that the two wires are perpendicular to the plane Bx and By are everywhere 0 on the plane.
a) Midway between, the Bz components cancel, so <0, 0, 0> T
b) Bz = µ₀ x I / 2πa + µ₀ x I / 2π(3a) = (µ₀ x I / 2π)(1/a + 1/3a)
Bz = (µ₀ x I / 2πr)(3/3a + 1/3a) = (µ₀x I / 2πr)(4 / 3a) = 2µ₀ x I / 3πa
c) By symmetry, Bz = -2µ₀ x I / 3πa (that is, down into the plane)
A peach, because it takes a longer process for the peach tree to form creating the peach! I hope this helps!!!