Given the function $$f$($x$)=$f$($x$)=$ x$3$x$2+2$x$3$x$2+2.$ Find the x$-$value$($s$)$ of the point$($s$)$ where the tangent line is horizontal.

$1\mathrm{.}00001\mathrm{.}0000$

$1\mathrm{.}0000,1\mathrm{.}00001\mathrm{.}0000,1\mathrm{.}0000$

$0\mathrm{.}5,0\mathrm{.}50\mathrm{.}5,0\mathrm{.}5$

$00$

$0,0\mathrm{.}6667$