I have a linear system with transfer function \$G(s)\$ that is connected in negative feedback with a real value gain \$K\$.
Therefore the open loop transfer function is \$K \cdot G(s)\$
and the closed loop transfer function is \$G(s) / (1 + K \cdot G(s))\$
My question is : "is there a way I can obtain the closed loop response of a change on the gain from \$K\$ to \$K + a\$ where \$a\$ is another real value ?"
Edit: I would like to obtain the response in the time domain where I can see the reaction of the system to the change of the gain from \$K\$ to \$K+a\$.