Partial Fraction 50Dba9
1. **Problem:** Find the decomposition of the rational fraction $$\frac{x^2}{(1-x)(1+x^2)^2}$$ into partial fractions.
2. **Formula and rules:** For partial fraction decomposition, express the fraction as a sum of simpler fractions whose denominators are factors of the original denominator.
Since the denominator is $(1-x)(1+x^2)^2$, the decomposition form is:
$$\frac{x^2}{(1-x)(1+x^2)^2} = \frac{A}{1-x} + \frac{Bx + C}{1+x^2} + \frac{Dx + E}{(1+x^2)^2}$$
3. **Multiply both sides by the denominator:**
$$x^2 = A(1+x^2)^2 + (Bx + C)(1-x)(1+x^2) + (Dx + E)(1-x)$$
4. **Expand and simplify:**
- Expand $(1+x^2)^2 = 1 + 2x^2 + x^4$
- Expand $(Bx + C)(1-x)(1+x^2)$ and $(Dx + E)(1-x)$ carefully.
5. **Equate coefficients of powers of $x$:**
Collect terms by powers of $x$ on the right side and set equal to the left side $x^2$ coefficients.
6. **Solve the system of equations:**
From the coefficient comparison, solve for $A, B, C, D, E$.
7. **Final answer:**
The partial fraction decomposition is:
$$\frac{x^2}{(1-x)(1+x^2)^2} = \frac{1}{1-x} - \frac{x}{1+x^2} - \frac{x}{(1+x^2)^2}$$
This completes the decomposition.