n electron$$s position is given by $=3\mathrm{.}0004\mathrm{.}000+2\mathrm{.}00,$ with t in seconds and $$ in meters.

$($a$)$ In unit$-$vector notation, what is the electron$$s velocity $()?$ At t $3\mathrm{.}00$ s$,$ what is $($b$)$ in unit vector notation and as $($c$)$ a magnitude and $($d$)$ an angle relative to the positive direction of the x axis?