$($Direct Comparison Tests$)$ Use the Direct Comparison Tests to determine whether

each series converges or diverges.

$($a$)\backslash$sum$\_($k$=1)^(\backslash$infty $)(3)/(4^($k$)+4)$;

$($b$)\backslash$sum$\_($k$=2)^(\backslash$infty $)(4^($k$))/(7^($k$)+1)$;

$($c$)\backslash$sum$\_($k$=1)^(\backslash$infty $)($sin$^(2)$k$)/($k$^($x$))$

$($d$)\backslash$sum$\_($k$=1)^(\backslash$infty $)(2)/($lnk$)$