I get -1 as the cube root of -1,which is correct. But if I put -1 in parentheses I get an imaginary result. I was hoping the imaginary result, if cubed, would give me -1, but it got worse.
-1^(1/3).n()
-1.00000000000000
(-1)^(1/3).n()
0.500000000000000 + 0.866025403784439*I
