Why won't the prime graph correctly?

[cyrille de brébisson]

Hello

The "problem" is that (-2)^0.4 is a complex number, not a real as most people have been lead to expect by their math teachers.

Prime does indeed graph the graph as mathematician would expect it.

power of a non decimal number is only equivalent to a nth root when x>=0, this "equivalence" does not carry on when x<0.

If you do want to calculate/draw the nth root, use the nthroot function.

Cyrille