Find the following for the given function: $(10$ points$)$

$f(x)=x^4-2x^{2}7$

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

Where the function is increasing: $$

Where the function is decreasing: $$

Location of local maxima: $x=$

Location of local minima: $x=$

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

Where the function is concave up: $$

Where the function is concave down: $$

Location of inflection points: $x=$