Math Problem Statement

Solve this z transform problem and explain the steps throughly

Solve this Z-transform problem and explain the steps thoroughly

Solution

Let's solve the given Z-transform problem step by step.

Problem:

We are given the function X(z)X(z) as: X(z)=1+12z1112z1X(z) = \frac{1 + \frac{1}{2}z^{-1}}{1 - \frac{1}{2}z^{-1}} We need to find the corresponding x(n)x(n), which is the inverse Z-transform of X(z)X(z).

Step-by-step solution:

  1. Given Expression: The given Z-transform is: X(z)=1+12z1112z1X(z) = \frac{1 + \frac{1}{2}z^{-1}}{1 - \frac{1}{2}z^{-1}} We need to express this in a form that allows us to find the inverse Z-transform.

  2. Break the Expression into Simpler Terms: Let's split the fraction into two terms. We can rewrite X(z)X(z) as: X(z)=1112z1+12z1112z1X(z) = \frac{1}{1 - \frac{1}{2}z^{-1}} + \frac{\frac{1}{2}z^{-1}}{1 - \frac{1}{2}z^{-1}} Now we have two terms that we can work with separately.

  3. Recognize the Inverse Z-transform Patterns: The two terms can now be interpreted using known inverse Z-transform pairs. Specifically:

    • The first term, 1112z1\frac{1}{1 - \frac{1}{2}z^{-1}}, is of the form 11az1\frac{1}{1 - az^{-1}}, whose inverse Z-transform is anu(n)a^n u(n), where u(n)u(n) is the unit step function. In this case, a=12a = \frac{1}{2}, so the inverse Z-transform is: x1(n)=(12)nu(n)x_1(n) = \left(\frac{1}{2}\right)^n u(n)

    • The second term, 12z1112z1\frac{\frac{1}{2}z^{-1}}{1 - \frac{1}{2}z^{-1}}, is of the form bz11az1\frac{bz^{-1}}{1 - az^{-1}}, whose inverse Z-transform is an1u(n1)a^{n-1} u(n-1). Here, b=12b = \frac{1}{2} and a=12a = \frac{1}{2}, so the inverse Z-transform is: x2(n)=12(12)n1u(n1)x_2(n) = \frac{1}{2} \left(\frac{1}{2}\right)^{n-1} u(n-1) Simplifying this gives: x2(n)=12nu(n1)x_2(n) = \frac{1}{2^n} u(n-1)

  4. Combine the Two Results: Now that we have the inverse Z-transforms of both parts, we can combine them to get the overall inverse Z-transform: x(n)=(12)nu(n)+12nu(n1)x(n) = \left(\frac{1}{2}\right)^n u(n) + \frac{1}{2^n} u(n-1)

This is the solution for x(n)x(n).


Summary of Steps:

  1. Start with the given Z-transform function.
  2. Break the expression into simpler terms.
  3. Recognize each term as a known Z-transform pair and apply inverse Z-transform rules.
  4. Combine the results to find the final time-domain sequence.

Would you like more details on any of these steps, or do you have any specific questions?


Relative Questions:

  1. How can you identify standard Z-transform pairs when solving problems?
  2. What is the significance of the unit step function u(n)u(n) in Z-transform problems?
  3. How does the splitting of fractions help in simplifying Z-transform problems?
  4. What is the physical interpretation of the Z-transform in signal processing?
  5. How do you handle Z-transforms when the denominator has higher powers of z1z^{-1}?

Tip:

Always look for standard Z-transform pairs (from tables) to simplify the process of finding inverse Z-transforms in complex expressions.

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Math Problem Analysis

Mathematical Concepts

Z-Transform
Inverse Z-Transform
Signal Processing
Partial Fractions

Formulas

X(z) = \frac{1 + \frac{1}{2}z^{-1}}{1 - \frac{1}{2}z^{-1}}
Inverse Z-transform of \frac{1}{1 - az^{-1}} = a^n u(n)
Inverse Z-transform of \frac{bz^{-1}}{1 - az^{-1}} = b a^{n-1} u(n-1)

Theorems

Linear time-invariant system theory
Unit step function

Suitable Grade Level

Undergraduate (Electrical Engineering or related fields)