Consider the function $f(x)=2x+8x^{-1}.$ For this function there are four important open intervals: $(-,A),(A,B),(B,C),$ and $(C,)$ where $A,$ and $C$ are the critical numbers and the function is not defined at $B.$

Find $A$

and $B$

and $C$

For each of the following open intervals, tell whether $f(x)$ is increasing or decreasing.

$(-,A)$: Select an answer $vv$

$(A,B)$: Select an answer $vv$

$(B,C)$: Select an answer $vv$

$(C,)$ :