Tích phân $\int\limits_{0}^{1}{\dfrac{2}{2x+1}\text{d}x}$ bằng

$\int\limits_{0}^{1}{\dfrac{2}{2x+1}\text{d}x}=\int\limits_{0}^{1}{\dfrac{(2x+1)'}{2x+1}\text{d}x}=\int\limits_{0}^{1}{\dfrac{\text{d}(2x+1)}{2x+1}=\ln \left| 2x+1 \right|}\left| \begin{aligned}
& 1 \\
& 0 \\
\end{aligned} \right.=\ln 3.$