Câu hỏi: Nếu $\int\limits_{0}^{1}{f\left( x \right)\text{d}x}=4$ thì $\int\limits_{0}^{1}{2f\left( x \right)\text{d}x}$ bằng A. $16$. B. $4$. C. $2$. D. $8$.
Ta có: $\int\limits_{0}^{1}{2f\left( x \right)\text{d}x}=2\int\limits_{0}^{1}{f\left( x \right)\text{d}x}=2.4=8$.