$3.$Give two examples each of functions that can be represented as

a$.$ O$($f$($n$))$ b$.($f$($n$))$ c$.\backslash$Omega $($f$($n$))$

$4.$ The function f$($x$)=$ n $+$ n$2+2$n $+$ n$4$ belongs in which of the

following complexity categories: $($a$)\backslash$theta $($n$)($b$)\backslash$theta $($n$2)$

$($c$)\backslash$theta $($n$3)$

$($d$)\backslash$theta $($n lg n$)($e$)\backslash$theta $($n$4)($f$)$ None of these