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int((2x+9))/((x+2)(x-3)^(2))dx...

`int((2x+9))/((x+2)(x-3)^(2))dx`

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To solve the integral \(\int \frac{2x + 9}{(x + 2)(x - 3)^2} \, dx\), we will use the method of partial fractions. Here’s a step-by-step solution: ### Step 1: Set up the partial fraction decomposition We want to express \(\frac{2x + 9}{(x + 2)(x - 3)^2}\) in the form: \[ \frac{A}{x + 2} + \frac{B}{x - 3} + \frac{C}{(x - 3)^2} \] where \(A\), \(B\), and \(C\) are constants to be determined. ### Step 2: Combine the fractions We can combine the right-hand side over a common denominator: \[ \frac{A}{x + 2} + \frac{B}{x - 3} + \frac{C}{(x - 3)^2} = \frac{A(x - 3)^2 + B(x + 2)(x - 3) + C(x + 2)}{(x + 2)(x - 3)^2} \] ### Step 3: Set the numerators equal Now, we set the numerators equal to each other: \[ 2x + 9 = A(x - 3)^2 + B(x + 2)(x - 3) + C(x + 2) \] ### Step 4: Expand the right-hand side Expanding the right-hand side: 1. \(A(x - 3)^2 = A(x^2 - 6x + 9)\) 2. \(B(x + 2)(x - 3) = B(x^2 - x - 6)\) 3. \(C(x + 2) = Cx + 2C\) Combining these gives: \[ Ax^2 - 6Ax + 9A + Bx^2 - Bx - 6B + Cx + 2C \] Combining like terms: \[ (A + B)x^2 + (-6A - B + C)x + (9A - 6B + 2C) \] ### Step 5: Set up a system of equations Now we equate coefficients from both sides: 1. Coefficient of \(x^2\): \(A + B = 0\) 2. Coefficient of \(x\): \(-6A - B + C = 2\) 3. Constant term: \(9A - 6B + 2C = 9\) ### Step 6: Solve the system of equations From \(A + B = 0\), we can express \(B\) in terms of \(A\): \[ B = -A \] Substituting \(B = -A\) into the other equations: 1. \(-6A - (-A) + C = 2 \Rightarrow -5A + C = 2\) 2. \(9A - 6(-A) + 2C = 9 \Rightarrow 15A + 2C = 9\) Now we have: 1. \(C = 5A + 2\) 2. Substituting into \(15A + 2(5A + 2) = 9\): \[ 15A + 10A + 4 = 9 \Rightarrow 25A = 5 \Rightarrow A = \frac{1}{5} \] Now substituting \(A\) back to find \(B\) and \(C\): \[ B = -\frac{1}{5}, \quad C = 5\left(\frac{1}{5}\right) + 2 = 3 \] ### Step 7: Write the partial fraction decomposition Thus, we have: \[ \frac{2x + 9}{(x + 2)(x - 3)^2} = \frac{1/5}{x + 2} - \frac{1/5}{x - 3} + \frac{3}{(x - 3)^2} \] ### Step 8: Integrate each term Now we can integrate each term separately: \[ \int \left( \frac{1/5}{x + 2} - \frac{1/5}{x - 3} + \frac{3}{(x - 3)^2} \right) dx \] 1. \(\int \frac{1/5}{x + 2} \, dx = \frac{1}{5} \ln |x + 2|\) 2. \(\int -\frac{1/5}{x - 3} \, dx = -\frac{1}{5} \ln |x - 3|\) 3. \(\int \frac{3}{(x - 3)^2} \, dx = -\frac{3}{x - 3}\) ### Step 9: Combine the results Combining these results gives: \[ \int \frac{2x + 9}{(x + 2)(x - 3)^2} \, dx = \frac{1}{5} \ln |x + 2| - \frac{1}{5} \ln |x - 3| - \frac{3}{x - 3} + C \] ### Final Answer Thus, the final answer is: \[ \frac{1}{5} \ln |x + 2| - \frac{1}{5} \ln |x - 3| - \frac{3}{x - 3} + C \]
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