Consider the following function.

$F(x)=x^{\frac{4}{5}}(x-9{)}^2$

Find the derivative of the function.

$F^{\text{'}}(x)=$

Find the values of $x$ such that $F^{\text{'}}(x)=0.($Enter your answers as a comma$-$separated list. If an answer does not exist, enter DNE.$)$

$x=$

Find the values of $x$ in the domain $F$ such that $F^{\text{'}}(x)$ does not exist. $($Enter your answers as a comma$-$separated list. If an answer does not exist, enter DNE.$)$

$x=$

Find the critical numbers of the function. $($Enter your answers as a comma$-$separated list. If an answer does not exist, enter DNE.$)$

$x=$