Poles and zeroes - $\mathcal Z$-transform

1. What is poles and zeros in Z-transform?
2. What is the formula for Z-transform?

What is poles and zeros in Z-transform?

Introduction to Poles and Zeros of the Z-Transform

The two polynomials, P(z) and Q(z), allow us to find the poles and zeros of the Z-Transform. The value(s) for z where P(z)=0. The complex frequencies that make the overall gain of the filter transfer function zero.

What is the formula for Z-transform?

Concept of Z-Transform and Inverse Z-Transform

X(Z)|z=ejω=F. T[x(n)].