Understanding Sensitivity in Negative Feedback: Definition and Explanation

[dhruv.tara]

Homework Statement

In study of negative feedback and stuff we define sensitivity as ration of the change in the fraction of gain with feedback to the fraction of gain without feedback. We get S = 1/(1+GH)

I was interested in knowing why did we choose to define it this way... Why not simply as ratio of change in the gain with feedback to change in gain without feedback? Then we'll get S=1/(1+GH)^2

Homework Equations

The Attempt at a Solution

 

[dhruv.tara]

someone reply please...