Question $4(15$ points$).$ Use the master method to give tight asymptotic bounds for the following

recurrences. $[$Rubrics: determine the asymptotic relationship of f$($n$)$ and $,$ based on the

relationship, check the $$cookbook$($master method$)$ and give the answer. $***$When a big$-$omega

relationship is found, the regularity condition needs to be verified.$]$

$($a$).()=5$

$4+2$

$($b$).()=2$

$4+1$

$($c$).()=27$

$3+23$