Find the derivative of the function with or without using the product or quotient rule.

$($a$)f(x)=\sqrt[\phantom{2}]{x}(x6)$

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

$$

$($b$)f(x)=\frac{x\sqrt[\phantom{2}]{x}}{x^6}$

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

$$