Lat $f(x)=\frac{x}{x^2+69}$

Find be crifacal points $c$ thar conreypond to local minima

$($Uhe symbolic motation and fractions where nouled. Give your answer in the form of a comma separated list. Bater DNE if there we no cribical pointe.$)$

Find the critical points $e$ that correspond to local matima.

$($Use symbotic notation and fractions where needed Give your answer it the form of a comma separated list. Enter DNE if there are no critical po$$nds$.)$ are no infoction points.$)$

Determine the interval on which $f$ is concane up

$($Use symbolic notation and fractions where neaded. Give your answer as interval in the form $(**,**).$ Use the symbol co for intinity, U for combining intervals, and an appropriate type of parenthesis $"(",")","[",$ "I" depending on whether the interval is open or clowed. Enter $$ if the interval is emply.$)$

Determine the interval on which $f$ is concave down.

$($Use symbolic aotation and fractions where needied. Give your answer as interval in the form $(**,*).$ Uhe the symbol co for infinity, $U$ for combining intervals, and an appropriate type of parenthesis $"$C$."".$ T$""$ T$"$ depending on whether the interval is cpea or closed. Enter $\frac{O}{?}$ if the interval is emply.$)$