Trouble evaluating the integral for a rational function

In summary, the conversation discusses a problem with evaluating an integral involving partial fraction methods. The goal is to find the value of A, B, and C in the equation (10x+2)/(x-5)(x^2+1). The suggested method is to equate the numerators and substitute values for x that will eliminate most of the constants.
  • #1
uwludd
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Homework Statement


i've tried many partial fraction methods but none of y answers are correct in the end, please help me evaluate the integral for f(x)= (10x+2)/(x-5)(x^2 + 1)


Homework Equations



there are no relevant equations given

The Attempt at a Solution



A/x-5 + Bx+C/x^2 +1
 
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  • #2
So now you have

[tex]\frac{A(x^2+1)+(Bx+C)(x-5)}{(x-5)(x^2+1)}= \frac{10x+2}{(x-5)(x^2+1)}[/tex]


So equating the numerators

A(x^2+1)+(Bx+C)(x-5)= 10x+2 for all values of x.

Try putting suitable values of x which will eliminate most of the constants. For example, x=5 will help you get A.
 

FAQ: Trouble evaluating the integral for a rational function

What is a rational function?

A rational function is a function that can be written as the quotient of two polynomials, where the denominator is not equal to zero. It can be written in the form f(x) = p(x)/q(x), where p(x) and q(x) are polynomials.

Why is it difficult to evaluate integrals for rational functions?

Evaluating integrals for rational functions can be difficult because there is no general rule or formula for finding the antiderivative of a rational function. It often requires a combination of algebraic manipulation and substitution to solve the integral.

What is the process for evaluating integrals for rational functions?

The process for evaluating integrals for rational functions involves finding the antiderivative of the function, which is also known as the indefinite integral. This can be done using various techniques, such as u-substitution, integration by parts, or partial fractions. Once the antiderivative is found, the definite integral can be evaluated by plugging in the limits of integration and subtracting the result at the lower limit from the result at the upper limit.

Can all rational functions be integrated?

No, not all rational functions can be integrated. Some functions have integrals that cannot be expressed in terms of elementary functions. These are known as non-elementary integrals and can only be approximated using numerical methods.

How can I check if I have correctly evaluated an integral for a rational function?

You can check if you have correctly evaluated an integral for a rational function by differentiating the result and checking if it gives you the original function. If it does, then you have solved the integral correctly. You can also use online integral calculators to verify your result.

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