Current Attempt in Progress

A particle's position is given by $x=18\mathrm{.}0-12\mathrm{.}00t+3t^2,$ in which $x$ is in meters and $t$ is in seconds. $($a$)$ What is its velocity at $t=1s?($b$)$ Is it moving in the positive or negative direction of $x$ just then? $($c$)$ What is its speed just then? $($d$)$ Is the speed increasing or decreasing just then? $($Try answering the next two questions without further calculation.$)($e$)$ Is there ever an instant when the velocity is zero? If so$,$ give the time $t$; if not, answer $"0".($f$)$ Is there a time after $t=3s$ when the particle is moving in the negative direction of $x?$ If so$,$ give the time $t$; if not, answer $"0".$

$($a$)$ Number Units

$($b$)$

$($c$)$ Number Units

$($d$)$

$($e$)$ Number Units

$($f$)$ Number

Units