Câu hỏi: Tính $I=\int\limits_{1}^{e}{\left( \dfrac{1}{x}-\dfrac{1}{{{x}^{2}}} \right)}\text{d}x.$ A. $I=\dfrac{1}{e}+1$. B. $I=1$. C. $I=e$. D. $I=\dfrac{1}{e}$.
Ta có: $I=\left. \left( \ln \left| x \right|+\dfrac{1}{x} \right) \right|_{1}^{e}=\dfrac{1}{e}$.
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