It's not. I got the same answer. If the intended answer is positive and the variable has a odd-numbered-exponent, then the answer has to be positive. (-4/3)^3 = -81/27. I'm just going to jump to the conclusion that you are overgeneralizing the need to add multiple answers (in the form of double and triple roots), which does not apply in this situation.
If you have a graphing calculator, you can confirm this by throwing in the function, Second-Trace, and going to the Zero option (set limits as close as possible to 0 for your min, and 10 for your max in ZStandard). It will give you 1.333.
EDIT: In ZStandard, it actually looks like a line. LAWLZ
THOSE WHO EDIT FURTHER: Maybe you should consolidate all of your math troubles into one thread, Britannia-man.







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