Math Problem Statement

Evaluate the integral \( \int \frac{x - 2}{(2x - 3)^2} \, dx \)

Solution

The integral given is:

x2(2x3)2dx\int \frac{x - 2}{(2x - 3)^2} \, dx

To solve this integral, we can use substitution. Let's proceed with the following steps:

  1. Substitute: Let u=2x3u = 2x - 3. Then, the derivative dudx=2\frac{du}{dx} = 2, or dx=du2dx = \frac{du}{2}.

  2. Rewrite x2x - 2 in terms of uu: Since u=2x3u = 2x - 3, we can solve for xx as follows: x=u+32x = \frac{u + 3}{2} Therefore, x2=u+322=u+342=u12x - 2 = \frac{u + 3}{2} - 2 = \frac{u + 3 - 4}{2} = \frac{u - 1}{2}

  3. Rewrite the integral in terms of uu: Substitute x2=u12x - 2 = \frac{u - 1}{2} and dx=du2dx = \frac{du}{2}: x2(2x3)2dx=u12u2du2\int \frac{x - 2}{(2x - 3)^2} \, dx = \int \frac{\frac{u - 1}{2}}{u^2} \cdot \frac{du}{2} Simplifying, this becomes:

    = \frac{1}{4} \int \left( \frac{u}{u^2} - \frac{1}{u^2} \right) du$$ $$= \frac{1}{4} \int \left( \frac{1}{u} - \frac{1}{u^2} \right) du$$
  4. Integrate: Now, we can integrate each term separately: =14(lnu+1u)+C= \frac{1}{4} \left( \ln |u| + \frac{1}{u} \right) + C

  5. Substitute back u=2x3u = 2x - 3: =14(ln2x3+12x3)+C= \frac{1}{4} \left( \ln |2x - 3| + \frac{1}{2x - 3} \right) + C

So, the solution is:

x2(2x3)2dx=14ln2x3+14(2x3)+C\int \frac{x - 2}{(2x - 3)^2} \, dx = \frac{1}{4} \ln |2x - 3| + \frac{1}{4(2x - 3)} + C

Would you like further details or have any questions?


Here are five related questions for further exploration:

  1. How would this integral change if the denominator was (2x3)3(2x - 3)^3 instead of (2x3)2(2x - 3)^2?
  2. Can we solve this integral using integration by parts instead of substitution?
  3. How does the solution differ if we integrate x+2(2x3)2\frac{x + 2}{(2x - 3)^2}?
  4. What if we integrate x2(2x3)n\frac{x - 2}{(2x - 3)^n} for an arbitrary power nn?
  5. How would we approach the integral if the numerator were a constant instead of x2x - 2?

Tip: When faced with rational functions in integrals, substitution is often useful, especially when the denominator’s structure can be simplified by redefining variables.

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Math Problem Analysis

Mathematical Concepts

Calculus
Integration
Substitution Method

Formulas

Substitution: Let u = 2x - 3, then \( du/dx = 2 \), or \( dx = \frac{du}{2} \)
Integral of \( \frac{1}{u} \): \( \int \frac{1}{u} \, du = \ln |u| + C \)
Integral of \( \frac{1}{u^2} \): \( \int \frac{1}{u^2} \, du = -\frac{1}{u} + C \)

Theorems

Fundamental Theorem of Calculus

Suitable Grade Level

Undergraduate Calculus