Google
Câu hỏi: Nếu $\int\limits_{0}^{2}{f\left( x \right)\text{d}x}=4$ thì $\int\limits_{0}^{2}{\left[ \dfrac{1}{2}f\left( x \right)+2 \right]\text{d}x}$ bằng
A. $2$.
B. $6$.
C. $4$.
D. $8$.
A. $2$.
B. $6$.
C. $4$.
D. $8$.
Ta có $\int\limits_{0}^{2}{\left[ \dfrac{1}{2}f\left( x \right)+2 \right]\text{d}x}=\dfrac{1}{2}\int\limits_{0}^{2}{f\left( x \right)\text{d}x}+2\int\limits_{0}^{2}{\text{d}x}=\dfrac{1}{2}.4+2\left. x \right|_{0}^{2}=2+2\left( 2-0 \right)=6$.
Đáp án B.