# Transfer Function: Magnitude and Phase of Complex Function

1. Aug 28, 2012

### mvpshaq32

1. The problem statement, all variables and given/known data

f(s) = f($\sigma$ + j$\omega$) = $\frac{1}{(1+s)^2}$

Find the magnitude and phase angle of f(j$\omega$)

2. Relevant equations

s = j$\omega$ is a substitution you can make, but I'm not sure if you are supposed to apply that here

3. The attempt at a solution

I tried substituting $\sigma$ + j$\omega$ into the function and applying s = j$\omega$.

Then I get

$\frac{1}{(\sigma + 1)^2 + 2s(\sigma + 1) + s^2}$

I have a feeling it's supposed to be a quadratic pole, but the form of this doesn't match the form of a quadratic pole exactly.

2. Aug 29, 2012

### rude man

If they ask for f(jw) and they give you f(σ + jw) then σ = 0. So yes, let s = jw and proceed.