What is the partial fraction expansion of the proper function X(z)= 1/...
Explanation: First we eliminate the negative powers of z by multiplying both numerator and denominator by z2.
Thus we obtain X(z)= z2/(z2-1.5z+0.5)
The poles of X(z) are p1=1 and p2=0.5. Consequently, the expansion will be
(X(z))/z = z/((z-1)(z-0.5)) = 2/((z-1) ) – 1/((z-0.5) )( obtained by applying partial fractions)
=>X(z)= 2z/(z-1)-z/(z-0.5).
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What is the partial fraction expansion of the proper function X(z)= 1/...
Partial Fraction Expansion of X(z)
The partial fraction expansion of a rational function is a representation of the function as a sum of simpler fractions. In this case, we want to find the partial fraction expansion of X(z) = 1/(1 - 1.5z^-1 + 0.5z^-2).
Step 1: Factor the denominator
We start by factoring the denominator of X(z): 1 - 1.5z^-1 + 0.5z^-2 = (1 - z^-1)(1 - 0.5z^-1).
Step 2: Write the partial fraction expansion
We can now write X(z) as a sum of two simpler fractions:
X(z) = A/(1 - z^-1) + B/(1 - 0.5z^-1)
where A and B are constants to be determined.
Step 3: Find the constants A and B
To find the constants A and B, we need to multiply both sides of the equation above by the common denominator:
X(z)(1 - z^-1)(1 - 0.5z^-1) = A(1 - 0.5z^-1) + B(1 - z^-1)
Simplifying this equation, we get:
X(z) = A + B - (A/2)z^-1 - (B/2)z^-1
Comparing the coefficients of z^-1 on both sides, we get:
- A/2 - B/2 = -1.5
- A/2 + B/2 = 0.5
Solving for A and B, we get:
A = -2/(1 - 0.5) = -4
B = 2/(1 - 1) = 2
Therefore, the partial fraction expansion of X(z) is:
X(z) = -4/(1 - z^-1) + 2/(1 - 0.5z^-1)
which can be simplified as:
X(z) = 2z/(z - 1) - z/(z - 0.5)
Therefore, the correct answer is option D: 2z/(z - 1) - z/(z - 0.5).