Simplifying Integration by Parts: Understanding the Solution

In summary, the conversation is about integrating ln(2x+1) using integration by parts. The student initially gets a solution of xln(2x+1)+\frac{1}2{}ln(2x+1)-x+C, but is bothered by not being able to simplify it to the solution of \frac{1}{2}(2x+1)ln(2x+1)-x+C. Another person suggests pulling out a common factor and using u-substitution to simplify the solution. The student thanks the person for their help.
  • #1
Jay9313
40
0

Homework Statement



∫ln(2x+1) Integrate by parts

Homework Equations



I got xln(2x+1)+[itex]\frac{1}2{}[/itex]ln(2x+1)-x+C

The Attempt at a Solution



The solution is [itex]\frac{1}{2}[/itex](2x+1)ln(2x+1)-x+C

I know the answers are the same,but it's bugging me that I can't simplify the first answer I got to the second answer. Can someone explain it to me?
 
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  • #2
Look at the first two terms of your answer. Is there a common factor there that you can pull out?
 
  • #3
ln(2x+1) But I don't see how that will help?
 
  • #4
Oh, you can pull the term out, substitute your x from your u substitution, combine some terms, and you get it! Thanks!
 
  • #5
Glad I could help :)
 

1. What is integration by parts?

Integration by parts is a method used in calculus to find the integral of a product of two functions. It is based on the product rule for differentiation and is used to simplify complex integrals.

2. When should I use integration by parts?

Integration by parts is useful when you have an integral that involves a product of two functions, and one of the functions is easier to integrate than the other.

3. How do I use integration by parts?

To use integration by parts, you need to choose which function to differentiate and which function to integrate. Then, you apply the formula: ∫u dv = uv - ∫v du. Repeat this process until the integral is simpler to solve.

4. What is the formula for integration by parts?

The formula for integration by parts is ∫u dv = uv - ∫v du, where u and v are functions and du and dv are their respective differentials.

5. What are some common mistakes to avoid when using integration by parts?

Some common mistakes when using integration by parts include choosing the wrong functions to differentiate and integrate, not simplifying the integral after each iteration, and forgetting to add the constant of integration at the end.

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