$\Omega_c$=cutoff analog frequency
In this example, what is going to be value of $\Omega_c$?
Some teachers in youtube are teaching this method:
$\Omega_c = ?$
$H(s) = \frac{\Omega_c}{(s-s_1)(s-s_2)(s-s_3)}$
Other people are doing this
$H(s) = \frac{N(s)}{D(s)}$
$N(s) = \left.\frac{D(s)}{\sqrt{1+\varepsilon^2}}\right|_{s=0}$ for even N
$N(s) = \left.D(s)\right|_{s=0}$ for odd N
Is this method correct?
$$\Omega_c = \frac{\Omega_p}{\left(\frac{1}{A_p^2}-1\right)^{1/2N}}$$
If I use this formula, then I get infinite analog cut off frequency. So, I don't think this is correct.
I am really confused in how to calculate cut off frequency. How do I calculate it?
