Lets assume that a=1: 6=5 K=2 Find the intersection with the imaginary axIs 4K(s+1) (s+52-s+4) s3+4s2+(4K-1)s+20+4K=0; 4)2+20+4K=0 3+(4K-1)0=0→0=0;02=4K-1 .=-1.5 -16K+4+20+4K=0 12K=24→K=2