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Ch. 7 - Transcendental Functions
Hass - Thomas' Calculus 15th Edition
Hass15th EditionThomas' CalculusISBN: 9780137616077Non è quello che usi tu?Cambia libro di testo
Capitolo 7, Problema 7.2.55

Evaluate the integrals in Exercises 39–56.
55. ∫dx/(2√x + 2x)

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Start by rewriting the integral to make it easier to work with. The integral is given as \(\int \frac{dx}{2\sqrt{x} + 2x}\). Factor out the common factor in the denominator: \(2(\sqrt{x} + x)\), so the integral becomes \(\int \frac{dx}{2(\sqrt{x} + x)}\).
Simplify the integral by factoring out the constant \(\frac{1}{2}\): \(\frac{1}{2} \int \frac{dx}{\sqrt{x} + x}\). This makes the integral \(\frac{1}{2} \int \frac{dx}{\sqrt{x} + x}\).
To handle the terms involving \(\sqrt{x}\) and \(x\), use the substitution \(t = \sqrt{x}\). Then, \(x = t^2\) and \(dx = 2t \, dt\). Substitute these into the integral to rewrite it in terms of \(t\).
After substitution, the integral becomes \(\frac{1}{2} \int \frac{2t \, dt}{t + t^2}\). Simplify the numerator and denominator inside the integral to get \(\int \frac{t}{t + t^2} \, dt\).
Simplify the integrand by factoring \(t\) in the denominator: \(t + t^2 = t(1 + t)\). Then the integrand becomes \(\frac{t}{t(1 + t)} = \frac{1}{1 + t}\). Now, the integral reduces to \(\int \frac{1}{1 + t} \, dt\), which is a standard integral.

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