[ Closed ] Graph doesn't display if functions involve imaginary numbers

It seems like graph doesn't plot any graph that involves imaginary numbers, even if the value is real. Some examples are included in the file. If you click trace, you can trace points on these functions, but if you click it won't snap to the invisible parts of the graph, and it won't display them.

Another example is something like re(sqrt(x)), or sqrt(x)*i. The functions seem to return correct numbers for negative values of x, and you can trace it and even generate evaluation tables which work correctly, but it won't display the graph.