Figure 29-50a shows, in cross section, two long, parallel wires carrying current and separated by distance L. The ratio i1/i2 of their currents is 4.00; the directions of the currents are not indicated. Figure 29-50b shows the y component By of their net magnetic field along the x axis to the right of wire 2.The vertical scale is set by Bys ! 4.0 nT, and the horizontal scale is set by xs ! 20.0 cm. (a) At what value of x , 0 is By maximum? (b) If i2 ! 3 mA, what is the value of that maximum? What is the direction (into or out of the page) of (c) i1 and (d) i2?