Well-definedness of rational exponents?

91 Views Asked by At

I am a little bit confused witht the definition of rational exponents. I believe that the definition of $a^{\frac pq}$ is $\sqrt[q]{a}^p.$ However, $\dfrac 26 = \dfrac 13$, yet $-1^{2/6}$ is undefined (or imaginary?), while $-1^{1/3}=-1.$ How do we resolve this situation?