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Ch. 8 - Techniques of Integration
Hass - Thomas' Calculus 15th Edition
Hass15th EditionThomas' CalculusISBN: 9780137616077Not the one you use?Change textbook
Chapter 8, Problem 8.6.2

Use the table of integrals at the back of the text to evaluate the integrals in Exercises 1–26.
∫ dx / (x √(x + 4))

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1
Identify the integral to solve: \(\int \frac{dx}{x \sqrt{x + 4}}\).
Consider a substitution to simplify the square root expression. Let \(t = \sqrt{x + 4}\), which implies \(t^2 = x + 4\).
Differentiate both sides with respect to \(x\) to find \(dx\) in terms of \(dt\): \(2t \frac{dt}{dx} = 1\), so \(dx = 2t \, dt\).
Rewrite the integral in terms of \(t\): replace \(x\) with \(t^2 - 4\) and \(dx\) with \(2t \, dt\), then simplify the integrand accordingly.
Use the table of integrals to find the integral of the resulting expression in \(t\), then substitute back \(t = \sqrt{x + 4}\) to express the answer in terms of \(x\).

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Integration Using Standard Integral Tables

Integral tables provide formulas for common integrals, allowing quick evaluation without performing integration from first principles. Recognizing the integral's form helps match it to a known formula, simplifying the process.
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Integrals Involving Radical Expressions

Integrals containing radicals such as √(x + c) often require special techniques or formulas. Understanding how to handle these radicals, including rationalizing or using trigonometric substitutions, is essential for evaluating such integrals.
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