Chapter 4: Problem 9
Calculate the indefinite integral. $$ \int(x+1)^{2} d x $$
Short Answer
Expert verified
The indefinite integral is \( \frac{x^3}{3} + x^2 + x + C \).
Step by step solution
01
Expand the Integrand
To solve the integral, start by expanding the expression \(x + 1\)^2. This gives us: \\[(x + 1)^2 = x^2 + 2x + 1\]
02
Integrate Each Term Separately
Now that we have \(x^2 + 2x + 1\), we can integrate each term separately: \- Integrate \(x^2\): \int x^2 \, dx = \frac{x^3}{3}\- Integrate \(2x\): \int 2x \, dx = x^2\- Integrate \(1\): \int 1 \, dx = x\.\Combine these results to get the integrated expression.
03
Combine the Results
Combine the integrals of each term: - \frac{x^3}{3} + x^2 + x\Don't forget to add the constant of integration, \C\. Thus, the indefinite integral is \[\frac{x^3}{3} + x^2 + x + C\].
04
Verify the Results
To verify, differentiate the result \[\frac{x^3}{3} + x^2 + x + C\] with respect to \(x\) and check that it matches the original expression: - \frac{d}{dx}\left(\frac{x^3}{3}\right) = x^2\ - \frac{d}{dx}(x^2) = 2x\ - \frac{d}{dx}(x) = 1\The result \(x^2 + 2x + 1\) matches the expanded form of the original integrand, confirming the solution is correct.
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Integration by Substitution
Integration by substitution is a powerful technique that aims to simplify integrals by making a smart substitution. It's like untangling a knot by finding a clever thread to pull. You replace a part of the integrand with a new variable, which often simplifies the integral into a form that's easier to work with.
Here’s how it works:
Here’s how it works:
- Identify a part of the integrand that can be substituted with a new variable, say \( u \).
- Express \( dx \) in terms of \( du \) by differentiating your substitution.
- Rewrite the entire integral in terms of \( u \) and \( du \).
- Integrate with respect to \( u \).
- Substitute back into the original variable.
Integration Techniques
Integration is a crucial tool in calculus, similar to finding the area under a curve. However, not all functions can be integrated directly, which is why different techniques exist to tackle various types of integrals.
Some common integration techniques include:
Some common integration techniques include:
- Basic Integrals: These involve straightforward functions like \( x^n \), where you integrate directly using power rules.
- Integration by Parts: Useful when an integrand is the product of two functions, relying on the product rule of differentiation.
- Partial Fraction Decomposition: Helps integrate rational functions by breaking them into simpler fractions.
- Trigonometric Substitution: Used for integrals involving expressions like \( \sqrt{a^2 - x^2} \).
Expanding Expressions
Expanding an expression can significantly simplify the process of integration, as seen in our example.
- Firstly, understand the expression: What does it represent?
- Next, rewrite it in a form that makes it easier to handle. For example, \((x+1)^2\) expands into \(x^2 + 2x + 1\).
- Once expanded, you integrate each term separately.