I'm trying to decide if simplifying sqrt(y^6) requires use of the absolute value bars. For example, the rule "nth root(u^n) = abs(u) when n is even" can be used to simplify sqrt(y^6) as sqrt[(y^3)^2]=abs(y^3). However, the rules of rational exponents can also be used to simplify sqrt(y^6) as (y^6)^1/2=y^(6/2)=y^3. So are the absolute value bars necessary when simplifying sqrt(y^6), or not? I know that the domain of sqrt(y^6) is [0,inf), so does this allow for the absolute value bars to be unnecessary?