Okay. So my assignment is due in an hour and i'm stuck on this last question. If I can get some help, I would greatly appreciate it. So the problem reads: The electric field of a dipole can be calculated by assuming the positive charge q is at z = a/2 and the negative charge -q is at z = -a/2 (x=y=0). The electric field along the z axis found by vector addition of the electric field from the individual charges. FInd an expression for the electric field. (Hint: 1 / (1+x)^2 ) is approximately equal to 1 - 2x for small x.) By what power of z does the electric field fall off? Okay. So from the problem, I know that I can solve using the equation: |E1| = (1/4∏ε0)(q1/r^2) but how do i associate z and r? I'm super confused. Please help me.