Answer
The integral of \( f(x) = \frac{x+2}{(x^{2}+1)(2x-1)} \) from 2 to 3 is approximately 0.1643.
Solution
Certainly! Let's address the two parts of your query:
1. **Finding the Coordinates of Point E:**
Unfortunately, the first part of your question seems incomplete as it references points and a diagram that aren't provided. To determine the coordinates of point \( E \), more information or a diagram is needed, such as the coordinates of points \( A \), \( B \), and \( C \), and the specific condition for the line parallel to \( AC \).
*If you can provide additional details or clarify the problem, I'd be happy to assist further!*
2. **Expressing \( f(x) = \frac{x+2}{(x^{2}+1)(2x-1)} \) as Partial Fractions and Evaluating the Integral:**
**a. Partial Fraction Decomposition:**
We aim to express \( f(x) \) as a sum of simpler fractions:
\[
\frac{x+2}{(x^{2}+1)(2x-1)} = \frac{Ax + B}{x^{2}+1} + \frac{C}{2x -1}
\]
**Steps:**
1. **Multiply both sides by \((x^{2}+1)(2x-1)\):**
\[
x + 2 = (Ax + B)(2x -1) + C(x^{2} +1)
\]
2. **Expand and simplify:**
\[
x + 2 = 2A x^{2} - A x + 2B x - B + C x^{2} + C
\]
\[
x + 2 = (2A + C) x^{2} + (-A + 2B) x + (-B + C)
\]
3. **Equate the coefficients of like terms:**
\[
\begin{cases}
2A + C = 0 \quad &(1) \\
-A + 2B = 1 \quad &(2) \\
-B + C = 2 \quad &(3)
\end{cases}
\]
4. **Solve the system of equations:**
From equation (1): \( C = -2A \)
Substitute \( C \) into equation (3):
\[
-B - 2A = 2 \quad \Rightarrow \quad B = -2A - 2
\]
Substitute \( B \) into equation (2):
\[
-A + 2(-2A -2) = 1 \quad \Rightarrow \quad -A -4A -4 = 1 \quad \Rightarrow \quad -5A = 5 \quad \Rightarrow \quad A = -1
\]
Then:
\[
C = -2(-1) = 2
\]
\[
B = -2(-1) - 2 = 0
\]
5. **Final Partial Fractions:**
\[
f(x) = \frac{-x}{x^{2}+1} + \frac{2}{2x -1}
\]
**b. Evaluating the Integral:**
We need to compute:
\[
\int_{2}^{3} f(x) \, dx = \int_{2}^{3} \left( -\frac{x}{x^{2}+1} + \frac{2}{2x -1} \right) dx
\]
**Steps:**
1. **Integrate term by term:**
\[
\int \left( -\frac{x}{x^{2}+1} \right) dx = -\frac{1}{2} \ln(x^{2} + 1) + C
\]
\[
\int \frac{2}{2x -1} dx = \ln|2x - 1| + C
\]
2. **Combine the results:**
\[
\int_{2}^{3} f(x) \, dx = \left[ -\frac{1}{2} \ln(x^{2} + 1) + \ln(2x -1) \right]_{2}^{3}
\]
3. **Evaluate the definite integral:**
\[
= \left( -\frac{1}{2} \ln(10) + \ln(5) \right) - \left( -\frac{1}{2} \ln(5) + \ln(3) \right)
\]
\[
= -\frac{1}{2} \ln(10) + \frac{3}{2} \ln(5) - \ln(3)
\]
4. **Calculate numerically:**
Using approximate natural logarithm values:
\[
\ln(10) \approx 2.302585093
\]
\[
\ln(5) \approx 1.609437912
\]
\[
\ln(3) \approx 1.098612289
\]
Substitute these values:
\[
-\frac{1}{2} \times 2.302585093 \approx -1.151292547
\]
\[
\frac{3}{2} \times 1.609437912 \approx 2.414156868
\]
\[
-1.098612289
\]
Combine them:
\[
-1.151292547 + 2.414156868 - 1.098612289 \approx 0.164252032
\]
5. **Final Answer (to 4 decimal places):**
\[
\int_{2}^{3} f(x) \, dx \approx 0.1643
\]
**Summary:**
\[
\int_{2}^{3} \frac{x+2}{(x^{2}+1)(2x-1)} \, dx \approx 0.1643
\]
Reviewed and approved by the UpStudy tutoring team
Explain
Simplify this solution