https://www.dsprelated.com/freebooks/filters/Pole_Zero_Analysis_I.html

Here is a little summary

"we can write the general transfer function for the recursive LTI digital filter as

(...)

In the same way that

can be factored into

we can factor the numerator and denominator to obtain.

Hope this helps!

Thanks.

]]>Just realized the conjugate pair was added in to replace the "pre-FOIL" coefficients, with the knowledge the imaginary part would cancel out, leaving real numbers. ]]>

can be factored to: (1-Z

with some algebra.

Would anyone have the algebra steps to arrive at that conclusion?

Im a bit confuse about how this was deduced.

Thanks!

Yan