Skip to main content
Ch. 5 - Systems of Equations and Inequalities
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Not the one you use?Change textbook
Chapter 6, Problem 8

In Exercises 1–8, write the form of the partial fraction decomposition of the rational expression. It is not necessary to solve for the constants. (7x2 -9x+3)/(x2+7)2

Verified step by step guidance
1
Identify the denominator and factor it if possible. Here, the denominator is x² + 72, which is already factored as (x^2 + 7)^2.
Since the denominator is a repeated irreducible quadratic factor, the partial fraction decomposition will include terms for each power of this factor up to 2.
For each power of the irreducible quadratic factor (x^2 + 7), write a numerator that is a linear polynomial: for the first power, use Ax + B, and for the second power, use Cx + D.
Set up the partial fraction decomposition as the sum of these terms: \(\frac{Ax + B}{x^2 + 7}\) + \(\frac{Cx + D}{(x^2 + 7)^2}\).
This form represents the partial fraction decomposition of the given rational expression without solving for the constants A, B, C, and D.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
2m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Partial Fraction Decomposition

Partial fraction decomposition is a method used to express a rational function as a sum of simpler fractions, making integration or other operations easier. It involves breaking down a complex rational expression into a sum of fractions with simpler denominators.
Recommended video:
4:07
Decomposition of Functions

Repeated Quadratic Factors

When the denominator contains a repeated irreducible quadratic factor, such as (x² + 7)², the decomposition includes terms with the quadratic factor raised to increasing powers. Each term has a linear numerator for quadratic factors, reflecting the factor's multiplicity.
Recommended video:
06:08
Solving Quadratic Equations by Factoring

Form of Numerators in Partial Fractions

For linear factors, numerators are constants; for irreducible quadratic factors, numerators are linear expressions (ax + b). This ensures the decomposition can represent the original rational function accurately before solving for constants.
Recommended video:
Guided course
05:45
Radical Expressions with Fractions