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11.4 Partial Fractions

Splitting one rational expression into simpler fractions, case by case for repeated linear and irreducible quadratic factors.

Algebra and Trigonometry 2e, 11.4 Partial Fractions

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41 exercises

11.4 Exercise 1

Find the least common denominator of the following rationals:

23, 512, and 118\frac{2}{3} , \frac{5}{12} , a n d \frac{1}{18}

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11.4 Exercise 3

Find the least common denominator of the following rational expressions:

x+1x+3\frac{x + 1}{x + 3} and 2x2-9\frac{2}{x^{2} - 9}

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11.4 Exercise 4

Solve the system of equations by elimination.

3x+y=52x-3y=7\left\{\begin{matrix} 3 x + y = 5 \\ 2 x - 3 y = 7 \end{matrix}\right

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Decomposing a Rational Function with Distinct Linear Factors

Decompose the given rational expression with distinct linear factors.

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11.4 Exercise 6

Find the partial fraction decomposition of the following expression.

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Decomposing with Repeated Linear Factors

Decompose the given rational expression with repeated linear factors.

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11.4 Exercise 8

Find the partial fraction decomposition of the expression with repeated linear factors.

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Decomposing P ( x ) Q ( x ) When Q(x) Contains a Nonrepeated Irreducible Quadratic Factor

Find a partial fraction decomposition of the given expression.

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11.4 Exercise 10

Find the partial fraction decomposition of the expression with a nonrepeating irreducible quadratic factor.

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Decomposing a Rational Function with a Repeated Irreducible Quadratic Factor in the Denominator

Decompose the given expression that has a repeated irreducible factor in the denominator.

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11.4 Exercise 12

Find the partial fraction decomposition of the expression with a repeated irreducible quadratic factor.

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11.4 Exercise 13

Can any quotient of polynomials be decomposed into at least two partial fractions? If so, explain why, and if not, give an example of such a fraction

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11.4 Exercise 15

Can you explain how to verify a partial fraction decomposition graphically?

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11.4 Exercise 17

Once you have a system of equations generated by the partial fraction decomposition, can you explain another method to solve it? For example if you had 7x+13 3 x 2 +8x+15 = A x+1 + B 3x+5 \frac{7 x + 13}{3 x^{2} + 8 x + 15} = \frac{A}{x + 1} + \frac{B}{3 x + 5}, we eventually simplify to 7x+13=A(3x+5)+B(x+1). 7 x + 13 = A \left(3 x + 5\right) + B \left(x + 1\right) . Explain how you could intelligently choose an x x -value that will eliminate either A A or B B and solve for A A and B. B .

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11.4 Exercise 19

Find the decomposition of the partial fraction for the nonrepeating linear factors.

3x−79 x 2 −5x−24 \frac{3 x −79}{x^{2} −5 x −24}

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11.4 Exercise 21

Find the decomposition of the partial fraction for the nonrepeating linear factors.

10x+47 x 2 +7x+10 \frac{10 x + 47}{x^{2} + 7 x + 10}

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11.4 Exercise 23

Find the decomposition of the partial fraction for the nonrepeating linear factors.

32x−11 20 x 2 −13x+2 \frac{32 x −11}{20 x^{2} −13 x + 2}

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11.4 Exercise 25

Find the decomposition of the partial fraction for the nonrepeating linear factors.

5x x 2 −9 \frac{5 x}{x^{2} −9}

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11.4 Exercise 27

Find the decomposition of the partial fraction for the nonrepeating linear factors.

6x x 2 −4 \frac{6 x}{x^{2} −4}

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11.4 Exercise 29

Find the decomposition of the partial fraction for the nonrepeating linear factors.

4x−1 x 2 −x−6 \frac{4 x −1}{x^{2} - x −6}

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11.4 Exercise 31

Find the decomposition of the partial fraction for the nonrepeating linear factors.

3x−1 x 2 −5x+6 \frac{3 x −1}{x^{2} −5 x + 6}

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11.4 Exercise 33

Find the decomposition of the partial fraction for the repeating linear factors.

x ( x−2 ) 2 \frac{x}{\left(x −2\right)^{2}}

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11.4 Exercise 35

Find the decomposition of the partial fraction for the repeating linear factors.

−24x−27 ( 4x+5 ) 2 \frac{−24 x −27}{\left(4 x + 5\right)^{2}}

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11.4 Exercise 37

Find the decomposition of the partial fraction for the repeating linear factors.

5−x ( x−7 ) 2 \frac{5 - x}{\left(x −7\right)^{2}}

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11.4 Exercise 39

Find the decomposition of the partial fraction for the repeating linear factors.

5 x 2 +20x+8 2x ( x+1 ) 2 \frac{5 x^{2} + 20 x + 8}{2 x \left(x + 1\right)^{2}}

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11.4 Exercise 41

Find the decomposition of the partial fraction for the repeating linear factors.

54 x 3 +127 x 2 +80x+16 2 x 2 ( 3x+2 ) 2 \frac{54 x^{3} + 127 x^{2} + 80 x + 16}{2 x^{2} \left(3 x + 2\right)^{2}}

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11.4 Exercise 43

Find the decomposition of the partial fraction for the irreducible nonrepeating quadratic factor.

4 x 2 +6x+11 ( x+2 )( x 2 +x+3 ) \frac{4 x^{2} + 6 x + 11}{\left(x + 2\right) \left(x^{2} + x + 3\right)}

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11.4 Exercise 45

Find the decomposition of the partial fraction for the irreducible nonrepeating quadratic factor.

−2 x 2 +10x+4 ( x−1 )( x 2 +3x+8 ) \frac{−2 x^{2} + 10 x + 4}{\left(x −1\right) \left(x^{2} + 3 x + 8\right)}

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11.4 Exercise 47

Find the decomposition of the partial fraction for the irreducible nonrepeating quadratic factor.

4 x 2 +17x−1 ( x+3 )( x 2 +6x+1 ) \frac{4 x^{2} + 17 x −1}{\left(x + 3\right) \left(x^{2} + 6 x + 1\right)}

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11.4 Exercise 49

Find the decomposition of the partial fraction for the irreducible nonrepeating quadratic factor.

4 x 2 +5x+3 x 3 −1 \frac{4 x^{2} + 5 x + 3}{x^{3} −1}

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11.4 Exercise 51

Find the decomposition of the partial fraction for the irreducible nonrepeating quadratic factor.

3 x 2 −7x+33 x 3 +27 \frac{3 x^{2} −7 x + 33}{x^{3} + 27}

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11.4 Exercise 53

Find the decomposition of the partial fraction for the irreducible nonrepeating quadratic factor.

4 x 2 +4x+12 8 x 3 −27 \frac{4 x^{2} + 4 x + 12}{8 x^{3} −27}

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11.4 Exercise 55

Find the decomposition of the partial fraction for the irreducible nonrepeating quadratic factor.

−2 x 3 −30 x 2 +36x+216 x 4 +216x \frac{−2 x^{3} −30 x^{2} + 36 x + 216}{x^{4} + 216 x}

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11.4 Exercise 57

Find the decomposition of the partial fraction for the irreducible repeating quadratic factor.

x 3 +6 x 2 +5x+9 ( x 2 +1 ) 2 \frac{x^{3} + 6 x^{2} + 5 x + 9}{\left(x^{2} + 1\right)^{2}}

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11.4 Exercise 59

Find the decomposition of the partial fraction for the irreducible repeating quadratic factor.

x 2 +5x+5 ( x+2 ) 2 \frac{x^{2} + 5 x + 5}{\left(x + 2\right)^{2}}

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11.4 Exercise 61

Find the decomposition of the partial fraction for the irreducible repeating quadratic factor.

x 2 +25 ( x 2 +3x+25 ) 2 \frac{x^{2} + 25}{\left(x^{2} + 3 x + 25\right)^{2}}

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11.4 Exercise 63

Find the decomposition of the partial fraction for the irreducible repeating quadratic factor.

5x+2 x ( x 2 +4 ) 2 \frac{5 x + 2}{x \left(x^{2} + 4\right)^{2}}

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11.4 Exercise 65

Find the decomposition of the partial fraction for the irreducible repeating quadratic factor.

2x−9 ( x 2 −x ) 2 \frac{2 x −9}{\left(x^{2} - x\right)^{2}}

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11.4 Exercise 67

Find the partial fraction expansion.

x 2 +4 ( x+1 ) 3 \frac{x^{2} + 4}{\left(x + 1\right)^{3}}

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11.4 Exercise 69

Perform the operation and then find the partial fraction decomposition.

7 x+8 + 5 x−2 − x−1 x 2 −6x−16 \frac{7}{x + 8} + \frac{5}{x −2} - \frac{x −1}{x^{2} −6 x −16}

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11.4 Exercise 71

Perform the operation and then find the partial fraction decomposition.

2x x 2 −16 − 1−2x x 2 +6x+8 − x−5 x 2 −4x \frac{2 x}{x^{2} −16} - \frac{1 −2 x}{x^{2} + 6 x + 8} - \frac{x −5}{x^{2} −4 x}

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Adapted from College Algebra © 2021 Rice University. Licensed under CC BY 4.0. Sources: College Algebra 2e, Algebra and Trigonometry 2e, Precalculus 2e, College Algebra with Corequisite Support 2e. Imported at revision 4922e46.