I can't seem to do this with partial fractions

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SUMMARY

The discussion centers on the integration of the function \(\frac{x}{(x+4)^{2}}\) using partial fractions. The user attempts to express the integrand as \(\frac{A}{(x+4)}+\frac{Bx+C}{(x+4)^{2}}\) but encounters a contradiction when substituting \(x=-4\), leading to the equation \(-4=0\). This indicates a misunderstanding in setting up the partial fraction decomposition. The correct approach involves ensuring that the coefficients \(A\), \(B\), and \(C\) are determined accurately through algebraic manipulation.

PREREQUISITES
  • Understanding of partial fraction decomposition
  • Familiarity with algebraic manipulation of rational functions
  • Basic knowledge of integration techniques
  • Ability to solve linear equations for coefficients
NEXT STEPS
  • Study the method of partial fraction decomposition in detail
  • Practice solving rational integrals using integration techniques
  • Learn how to determine coefficients \(A\), \(B\), and \(C\) through algebraic equations
  • Explore common pitfalls in algebraic manipulations during integration
USEFUL FOR

Students studying calculus, particularly those focusing on integration techniques, as well as educators seeking to clarify concepts related to partial fractions.

skyturnred
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Homework Statement



[itex]\frac{x}{(x+4)^{2}}[/itex]

Homework Equations





The Attempt at a Solution



I make the integrand equal to the following:

[itex]\frac{A}{(x+4)}[/itex]+[itex]\frac{Bx+C}{(x+4)^{2}}[/itex]

Then after finding a common denominator I get

x = A(x+4)[itex]^{2}[/itex]+(Bx+C)(x+4)

But that cannot be possible because when you set x=-4, you get -4=0. Any help please?

Also if you have ANY tips whatsoever about partial fractions please tell me them!
 
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skyturnred said:

Homework Statement



[itex]\frac{x}{(x+4)^{2}}[/itex]

Homework Equations





The Attempt at a Solution



I make the integrand equal to the following:

[itex]\frac{A}{(x+4)}[/itex]+[itex]\frac{Bx+C}{(x+4)^{2}}[/itex]

Then after finding a common denominator I get

x = A(x+4)[itex]^{2}[/itex]+(Bx+C)(x+4)

But that cannot be possible because when you set x=-4, you get -4=0. Any help please?

Also if you have ANY tips whatsoever about partial fractions please tell me them!
Algebra check:

[itex]\displaystyle\frac{x}{(x+4)^{2}}=\frac{A}{(x+4)}+ \frac{Bx+C}{(x+4)^{2}}[/itex]

Multiplying by (x+4)2 gives:

[itex]\displaystyle x=A(x+4)+Bx+C[/itex]
 

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