4.2.4 Repeated Irreducible Quadratic Factors

4.2.4 Resolution of a fraction when $D(x)$ has repeated irreducible quadratic factors.

Rule IV: If a quadratic factor $(ax^{2} + bx + c)$ with $a \neq 0$ , occurs twice in the denominator, the corresponding partial fractions are

The constants $A, B, C$ and $D$ are found in the usual way.