Math Problem Statement

Evaluate the integral \( \int \frac{1}{2x + 5} \, dx \).

Solution

The integral given is:

12x+5dx\int \frac{1}{2x + 5} \, dx

To solve this integral, we can use a substitution method.

Solution

  1. Let u=2x+5u = 2x + 5.

    • Then, dudx=2\frac{du}{dx} = 2 or dx=du2dx = \frac{du}{2}.
  2. Substitute uu and dxdx in the integral: 12x+5dx=1udu2\int \frac{1}{2x + 5} \, dx = \int \frac{1}{u} \cdot \frac{du}{2}

  3. Simplify the integral: =121udu= \frac{1}{2} \int \frac{1}{u} \, du

  4. Now integrate: =12lnu+C= \frac{1}{2} \ln |u| + C

  5. Substitute back u=2x+5u = 2x + 5: =12ln2x+5+C= \frac{1}{2} \ln |2x + 5| + C

Final Answer

12x+5dx=12ln2x+5+C\int \frac{1}{2x + 5} \, dx = \frac{1}{2} \ln |2x + 5| + C

Would you like further details on this solution, or do you have any questions?

Here are some related questions for further practice:

  1. How would the integral change if the denominator were 3x+53x + 5 instead of 2x+52x + 5?
  2. How do we handle integrals of functions like 1ax+bdx\int \frac{1}{ax + b} \, dx in general?
  3. What is the role of substitution in solving integrals, and why is it useful?
  4. How would the solution differ if the integral were 1x2+5dx\int \frac{1}{x^2 + 5} \, dx instead?
  5. What would be the steps to solve 22x+5dx\int \frac{2}{2x + 5} \, dx?

Tip: When dealing with integrals of rational functions, look for substitution opportunities to simplify the expression.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Integration
Substitution Method

Formulas

\( \int \frac{1}{ax + b} \, dx = \frac{1}{a} \ln |ax + b| + C \)

Theorems

Logarithmic Integration Rule

Suitable Grade Level

Grades 11-12