Plot Complex Roots
pts = ComplexExpand[z /. Solve[z ^ 3 - 27 I == 0]]Show[ComplexContourPlot[Abs[z ^ 3 - 27 I], {z, 4}, Contours -> 15], ComplexListPlot[pts -> pts], ImageSize -> Medium]Show[ComplexContourPlot[Arg[z ^ 3 - 27 I], {z, 4}, Contours -> 15, ColorFunction -> "Rainbow"], ComplexListPlot[pts -> pts], ImageSize -> Medium]