Outputs incorrect answers when dealing with negative numbers and fractional exponents

[Former user]

Originally reported on Google Code with ID 391 ``` What steps will reproduce the problem? 1.Type -8^(1/3) into the box 2.Press Enter

What is the expected output? What do you see instead? -2 is the expected output. NaN is the answer given

What version of the product are you using? On what operating system? I am using 0.10.1 on Windows 7

Please provide any additional information below.

```

Reported by `Reillyandpie` on 2011-11-17 02:27:53

[Former user]

Reported by `helder.pereira.correia` on 2011-11-27 01:55:04 - Status changed: `Duplicate` - Merged into: #160