Eroxl's Notes
Partial Fraction Decomposition

A proper fraction with the product of irreducible polynomials in the denominator can be factored into a sum of fractions of the form , where and are some polynomials.

Generally this can be written as:

Given a fraction of the form where .

Where and are some polynomial.

Procedure

For each irreducible polynomial in the denominator a set of fractions is added to the sum based on one of three cases.

Case 1 - Single Linear Factor

Given a factor of the form it's term in the partial fraction decomposition is a term of the form:

Where is some constant.

Case 2 - Linear Factor to a Power

Given a factor of the form it's term in the partial fraction decomposition is a sum of the following form:

Where is some constant.

Example

Given the linear factor of it's terms assuming it's irreducible, are

Where , , , and are some constants.

Case 3 - Irreducible Non-Linear Factor

Given a factor that is an irreducible polynomial of degree , the corresponding term in the partial fraction decomposition is of the form:

where is a polynomial of degree one less than

Example

For a denominator containing the irreducible cubic factor , the corresponding term in the decomposition would be:

where , and are some constants.

Case 4 - Irreducible Non-Linear Factor to a Power

If the denominator contains a repeated irreducible polynomial factor , the corresponding terms in the partial fraction decomposition take the form:

where each is a polynomial of degree one less than

Example

For a denominator containing , the corresponding terms in the partial fraction decomposition would be:

where , , , , , and are some constants.