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Ch. 8 - Integration Techniques
Briggs - Calculus: Early Transcendentals 3rd Edition
Briggs3rd EditionCalculus: Early TranscendentalsISBN: 9780136847243Non è quello che usi tu?Cambia libro di testo
Capitolo 8, Problema 8.9.50

7–58. Improper integrals Evaluate the following integrals or state that they diverge.
50. ∫ (from 0 to 9) 1/(x - 1)¹ᐟ³ dx

Guida verificata passo dopo passo
1
Identify the type of integral and check for any points of discontinuity or singularities within the interval of integration. Here, the integrand is \(\frac{1}{(x - 1)^{1/3}}\), and the interval is from 0 to 9. Notice that the function is undefined at \(x = 1\) because the denominator becomes zero there.
Since \(x = 1\) lies within the interval of integration, split the integral at this point to handle the improper integral properly. Write the integral as the sum of two integrals: \(\int_0^1 \frac{1}{(x - 1)^{1/3}} \, dx + \int_1^9 \frac{1}{(x - 1)^{1/3}} \, dx\).
Rewrite each integral as a limit approaching the point of discontinuity. For the first integral, express it as \(\lim_{t \to 1^-} \int_0^t \frac{1}{(x - 1)^{1/3}} \, dx\). For the second integral, express it as \(\lim_{s \to 1^+} \int_s^9 \frac{1}{(x - 1)^{1/3}} \, dx\).
Find the antiderivative of the integrand \(\frac{1}{(x - 1)^{1/3}}\). Recall that \(\int (x - a)^n \, dx = \frac{(x - a)^{n+1}}{n+1} + C\) for \(n \neq -1\). Here, \(n = -\frac{1}{3}\), so the antiderivative is \(\frac{(x - 1)^{2/3}}{\frac{2}{3}} + C = \frac{3}{2} (x - 1)^{2/3} + C\).
Evaluate each limit by substituting the antiderivative back into the definite integrals and taking the limits as \(t \to 1^-\) and \(s \to 1^+\). Determine whether these limits converge to finite values or diverge to infinity to conclude if the original integral converges or diverges.

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