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Ch. 8 - Techniques of Integration
Hass - Thomas' Calculus 15th Edition
Hass15th EditionThomas' CalculusISBN: 9780137616077Non è quello che usi tu?Cambia libro di testo
Capitolo 8, Problema 8.4.12

Evaluate the integrals in Exercises 1–14.
∫ √(y² - 25) / y³ dy, where y > 5

Guida verificata passo dopo passo
1
Identify the integral to solve: \(\int \frac{\sqrt{y^{2} - 25}}{y^{3}} \, dy\), with the condition \(y > 5\).
Recognize that the integrand contains a square root of the form \(\sqrt{y^{2} - a^{2}}\), which suggests using a trigonometric substitution. Since \(y > 5\), set \(y = 5 \sec(\theta)\), where \(\theta\) is in the appropriate domain to keep \(y > 5\).
Compute the differential \(dy\) in terms of \(d\theta\): \(dy = 5 \sec(\theta) \tan(\theta) \, d\theta\).
Rewrite the integral in terms of \(\theta\) by substituting \(y = 5 \sec(\theta)\) and \(dy\) as above. Simplify the expression inside the square root and the powers of \(y\) accordingly.
Simplify the resulting integral using trigonometric identities, then integrate with respect to \(\theta\). After integration, substitute back \(\theta = \sec^{-1}(\frac{y}{5})\) to express the answer in terms of \(y\).

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