# determinant of transfer function

Discussion in 'Homework Help' started by bhuvanesh, Jan 29, 2015.

1. ### bhuvanesh Thread Starter Member

Aug 10, 2013
268
2
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

2. ### Veracohr Well-Known Member

Jan 3, 2011
559
77
It's saying the output amplitude is the same as the input amplitude. But that transfer function does do something useful...

Mar 6, 2009
5,448
783

4. ### MrAl Distinguished Member

Jun 17, 2014
2,561
517
Hi,

Are you sure it was 1-jw/1+jw ?
I ask because that jw/1 looks suspicious. It is unusual to show a '1' in the denominator because that just means it simplifies into just the numerator.
1-jw/(1+jw)

I am not saying that this is definite, just that it could have been read wrong or even printed wrong on the source page.
No problems if it was correct all along.

Of course it could also have been:
(1-jw)/(1+jw)

which would also make more sense, but it's a good idea to show all the parens when writing these mathematical expressions out.

5. ### Veracohr Well-Known Member

Jan 3, 2011
559
77
That's what I assumed.