Cho hàm số \(f\left(x\right)=\dfrac{1}{\sqrt{2x+1}}\). Khẳng định nào sau đây đúng?
\(\int f\left(x\right)\text{d}x=\sqrt{2x+1}+C\).\(\int f\left(x\right)\text{d}x=2\sqrt{2x+1}+C\).\(\int f\left(x\right)\text{d}x=\dfrac{1}{2}\sqrt{2x+1}+C\).\(\int f\left(x\right)\text{d}x=\dfrac{1}{\sqrt{2x+1}}+C\).Hướng dẫn giải:\(\int f\left(x\right)\text{d}x=\int\dfrac{1}{\sqrt{2x+1}}\text{d}x=\int\dfrac{\text{d}\left(2x+1\right)}{2\sqrt{2x+1}}=\sqrt{2x+1}+C\).
