To integrate the expression \(\frac{(2x^4 + 4x^3)dx}{(x^4 + x + 1)^2}\), we can use a technique called substitution, which simplifies the integration process. Let's break it down step by step.
Step 1: Identify a Suitable Substitution
In this case, we notice that the denominator is \((x^4 + x + 1)^2\). A good strategy is to let \(u = x^4 + x + 1\). This means that we will need to find \(du\) in terms of \(dx\).
Finding \(du\)
To find \(du\), we differentiate \(u\) with respect to \(x\):
Now, we can express \(dx\) in terms of \(du\):
- From \(du = (4x^3 + 1)dx\), we have \(dx = \frac{du}{4x^3 + 1}\).
Step 2: Substitute into the Integral
Now, we can substitute \(u\) and \(dx\) into the integral:
- The numerator \(2x^4 + 4x^3\) can be rewritten as \(2(x^4 + x + 1) + 2(4x^3 - 2x)\) using our substitution.
Thus, the integral becomes:
\(\int \frac{(2u + 2(4x^3 - 2x))}{u^2} \cdot \frac{du}{4x^3 + 1}\)
Step 3: Simplifying the Integral
Now we can simplify the integral further. The term \((4x^3 + 1)\) in the denominator will cancel out with the \(4x^3\) part in the numerator. This gives us:
\(\int \frac{2}{u} du + \int \frac{2(4x^3 - 2x)}{u^2(4x^3 + 1)} du\)
Integrating the First Term
The first integral, \(\int \frac{2}{u} du\), is straightforward:
- This evaluates to \(2 \ln |u| + C_1\).
Step 4: Addressing the Second Integral
The second integral is more complex, but we can evaluate it using partial fractions or further substitution if necessary. However, since it involves \(x\) terms, we may need to revert back to \(x\) after integrating.
Final Steps
After integrating both parts, we substitute back \(u = x^4 + x + 1\) into our results. The final answer will be a combination of the logarithmic term and the result from the second integral, which may require additional steps depending on its complexity.
Final Result
The complete integral will yield a result in terms of \(x\) and may look something like:
\(2 \ln |x^4 + x + 1| + \text{(result from the second integral)} + C\)
In summary, the integration process involves substitution, simplification, and careful handling of the resulting expressions. Each step builds on the previous one, leading to a comprehensive solution. If you have any questions about specific parts of the process, feel free to ask!