Partial fractions and integral

In summary, the conversation discusses the use of partial fractions in solving a given integral. The attempt at a solution involves using partial fractions, but there is uncertainty about how to find the necessary variables. The conversation ends with a request for the person to show their working so they can be guided in identifying where they may have made a mistake.
  • #1
nameVoid
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Homework Statement



I((3x^2+x+4)/(x^4+3x^2+2),x)
I((3x^2+x+4)/((x^2+1)(x^2+2)),x)
I(3x^2/((x^2+1)(x^2+2)),x)+I((x+4)/((x^2+1)(x^2+2)),x)
from here i have used partial fractions with no luck

Homework Equations





The Attempt at a Solution

 
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  • #2


It is probably easier to use partial fractions right after you get to:

[tex]\int \frac{ 3x^2 + x+4}{(x^2+1)(x^2+2)} dx[/tex].

Please show us your working so we can tell you where you went wrong.
 
  • #3


[tex]\frac{ 3x^2 + x+4}{(x^2+1)(x^2+2)}= \frac{Ax+ B}{x^2+ 1}+ \frac{Cx+ D}{x^2+ 2}[/tex]
Now, what did you do to try to find A, B, C, and D?
 

FAQ: Partial fractions and integral

What is partial fraction decomposition?

Partial fraction decomposition is a method used to break down a rational function into simpler fractions. It involves representing the function as a sum of simpler fractions with distinct denominators.

When is partial fraction decomposition used?

Partial fraction decomposition is often used when integrating rational functions, as it can simplify the integration process. It is also used in solving systems of linear equations and in solving differential equations.

How is partial fraction decomposition performed?

Partial fraction decomposition involves finding the partial fraction form of a rational function by equating its coefficients to the coefficients of simpler fractions. The coefficients can be found by using algebraic manipulation or by using the method of undetermined coefficients.

What is the difference between proper and improper partial fractions?

In proper partial fractions, the degree of the numerator is less than the degree of the denominator. In improper partial fractions, the degree of the numerator is equal to or greater than the degree of the denominator. Improper partial fractions can be converted to proper fractions by long division before performing partial fraction decomposition.

Are there any limitations to using partial fraction decomposition?

Partial fraction decomposition can only be used for rational functions, where the numerator and denominator are both polynomials. It cannot be used for functions with non-polynomial terms, such as trigonometric or logarithmic functions.

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