Question #f8d17

1 Answer
Sep 5, 2014

First of all, you have put this question in the wrong section. The answer for the domain is x in RR for f(x)=(x-4)^(1/3).

This is a different case than f(x)=sqrt(x-4) because a real number times itself can never be negative, eg. x*x!=-2. This is always the case with even roots.

However, it is not the case with odd roots. We can find an x such that x*x*x=-8, the answer is x=-2. Therefore the domain is not restricted for odd roots.

In general, for odd roots of positive values will have a positive answer and odd roots of negative values will have a negative answer.