Math Problem Statement

Using long division method, find the inverse Z-transform of 10z−1 10z (z−1)(z−2)

Solution

To find the inverse Z-transform of the given expression using the long division method, we begin by simplifying the expression and applying the method to determine the inverse. Let's start with the expression:

10z1(z1)(z2)\frac{10z^{-1}}{(z-1)(z-2)}

Step 1: Rewrite the expression.

The given expression can be rewritten as:

X(z)=10z(z1)(z2)X(z) = \frac{10z}{(z-1)(z-2)}

Step 2: Perform long division.

Now, we divide 10z10z by (z1)(z2)(z-1)(z-2). We need to express this as a power series, which will give us the inverse Z-transform in terms of a sequence. First, expand (z1)(z2)(z-1)(z-2):

(z1)(z2)=z23z+2(z-1)(z-2) = z^2 - 3z + 2

Now, perform long division of 10z10z by z23z+2z^2 - 3z + 2.

  1. Divide 10z10z by z2z^2, which gives us 10z\frac{10}{z}.

  2. Multiply 10z\frac{10}{z} by z23z+2z^2 - 3z + 2, and subtract this from 10z10z.

    10z×(z23z+2)=10z30+20z\frac{10}{z} \times (z^2 - 3z + 2) = 10z - 30 + \frac{20}{z}

    Subtract from 10z10z, we get:

    (10z10z)+3020z=3020z(10z - 10z) + 30 - \frac{20}{z} = 30 - \frac{20}{z}

Now, divide 3020z30 - \frac{20}{z} by z23z+2z^2 - 3z + 2. This process can be continued, but we are now generating a series. Each term generated gives us a term in the Z-transform sequence.

Step 3: Find the inverse Z-transform.

The inverse Z-transform is the sequence whose Z-transform corresponds to the power series we generate from long division.

In this case, the inverse Z-transform will be a series involving terms like 10,30,20,10, -30, 20, \dots. These terms correspond to the coefficients found in the long division process.

Final Answer:

The inverse Z-transform is the sequence:

x[n]=10,30,20,x[n] = 10, -30, 20, \dots

Would you like to go through the division process step-by-step with more details?


Next Steps:

  1. Would you like to see the complete long division for each step?
  2. Do you want to review Z-transform properties?
  3. Would you like a recap on how power series relate to Z-transforms?
  4. Should we explore a different method of finding the inverse Z-transform?
  5. Would you prefer an example with simpler terms?

Tip: The long division method converts the Z-transform into a power series where each term can be easily interpreted as part of the sequence corresponding to the inverse Z-transform.

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Math Problem Analysis

Mathematical Concepts

Z-transform
Inverse Z-transform
Long Division
Power Series

Formulas

X(z) = 10z / (z-1)(z-2)
Long division of polynomials
Inverse Z-transform using power series expansion

Theorems

Z-transform definition
Inverse Z-transform properties
Power Series Expansion

Suitable Grade Level

Undergraduate - Engineering/Applied Mathematics