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Ch. 7 - Transcendental Functions
Hass - Thomas' Calculus 15th Edition
Hass15th EditionThomas' CalculusISBN: 9780137616077당신이 사용하는 게 아니라요?교과서 변경
7장, 문제 7.3.45

Evaluate the integrals in Exercises 33–54.
∫ (e^(1/x) / x²) dx

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Identify the integral to solve: \(\int \frac{e^{1/x}}{x^{2}} \, dx\).
Look for a substitution that simplifies the exponent and the denominator. Notice that the exponent is \(\frac{1}{x}\), so let \(u = \frac{1}{x}\).
Compute the differential \(du\) in terms of \(dx\): Since \(u = x^{-1}\), then \(du = -x^{-2} \, dx\), or equivalently, \(-du = x^{-2} \, dx\).
Rewrite the integral in terms of \(u\) and \(du\): Substitute \(e^{1/x} = e^{u}\) and \(x^{-2} \, dx = -du\), so the integral becomes \(\int e^{u} (-du) = -\int e^{u} \, du\).
Integrate with respect to \(u\): The integral of \(e^{u}\) is \(e^{u}\), so the integral becomes \(-e^{u} + C\). Finally, substitute back \(u = \frac{1}{x}\) to express the answer in terms of \(x\).

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주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

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Intro to the Chain Rule

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Exponential functions with variable exponents, such as e^(1/x), require careful handling during integration. Understanding how to differentiate and integrate these functions, often through substitution, is essential to solving integrals involving such expressions.
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