Is it better to have radicals or fractional exponents in a simplified answer?
Is there a general convention?
depends of course
but ussually in answers that have exponents
is to use the $\displaystyle \sqrt{x} $ rather than
$\displaystyle x^{\frac{1}{2}}$ as an example
and have the radicals in the numerator
if there are exponents in the answer you want them to be positive.
do you have example of what you need to do.