power of negative numbers with fraction exponent

[cAsk]

hi,

why can't i power negative numbers with fractional exponent?
for example, (-2)^(4/3) gives me an error on the calculator while 2^(4/3) is ok

 

[stapel]

why can't i power negative numbers with fractional exponent?
for example, (-2)^(4/3) gives me an error on the calculator while 2^(4/3) is ok

I think this result will vary with the model of calculator. Try asking some fellow students; I'd be surprised if you didn't find a classmate whose calculator did not choke on the first expression above.

 

[pka]

Your calculator is too cheap

https://www.google.ca/?gws_rd=ssl#q=(-2)^(4/3)=

Come on Denis, http://www.wolframalpha.com/input/?i=(-2)^(4/3)+real

 

[cAsk]

Come on Denis, http://www.wolframalpha.com/input/?i=(-2)^(4/3)+real

thanks for your answers

i actually tried it on wolfram too, but i just don't get it - why is the result a complex numer?!
(-2)^(4/3) = (-2)*(-2)^(1/3) and it should be a positive real number....