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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 7.8.3g

3. Which of the following functions grow faster than x² as x→∞? Which grow at the same rate as x²? Which grow slower?
g. x^3 e^(-x)

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1
Identify the function given: \(g(x) = x^{3} e^{-x}\).
Recall that as \(x \to \infty\), the exponential term \(e^{-x}\) approaches 0 very rapidly, while the polynomial term \(x^{3}\) grows without bound but at a much slower rate compared to exponentials.
Analyze the behavior of \(g(x)\) by considering the dominant terms: since \(e^{-x}\) decays faster than any polynomial grows, the product \(x^{3} e^{-x}\) tends to 0 as \(x \to \infty\).
Compare this behavior to \(x^{2}\): since \(g(x)\) tends to 0 and \(x^{2}\) tends to infinity, \(g(x)\) grows slower than \(x^{2}\) as \(x \to \infty\).
Conclude that \(g(x)\) grows slower than \(x^{2}\) as \(x\) approaches infinity.

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