determinant of transfer function

[bhuvaneshnick]

i am studying control system i crossed this transfer function

H(jw)=(1-jw/1+jw)

now taking determinant of this

|H(jw)|=1

My question in what way the determinant is usefull to learn about the systrem.Here the determinant of transfer function is 1,so the 1 saying anything about the system

 

[steveB]

Ussually we call that operation "taking the magnitude" rather than "taking the determinant".

The magnigude of H(jw) tells the magnitude response for sine waves driving the system. A sine wave drives the input and another sine wave with a partiular magnitude and phase comes out. |H(jw)| tells the ratio of magnitudes as output over input. A magnitude response of 1 is an all-pass filter. That filter might modify the phase of the output, but the magnitude is unalterred.