Problem $3$: Draw accurate plot of the root locus for the negative feedback configuration with the following open$-$loop transfer function

$G(s)H(s)=\frac{k}{(s+1{)}^2(s+1+j\sqrt[\phantom{2}]{18})(s+1-j\sqrt[\phantom{2}]{18})}$

Also, find the range of $k$ for stability of the closed$-$loop system.