Google
Câu hỏi: Nếu $\int\limits_{0}^{2}{f\left( x \right)\text{d}x}=3$ và $\int\limits_{0}^{5}{f\left( x \right)\text{d}x}=6$ thì $\int\limits_{2}^{5}{f\left( x \right)\text{d}x}$ bằng
A. 18.
B. 3.
C. 9.
D. $-3$.
A. 18.
B. 3.
C. 9.
D. $-3$.
Ta có $\int\limits_{0}^{5}{f\left( x \right)\text{d}x}=\int\limits_{0}^{2}{f\left( x \right)\text{d}x}+\int\limits_{2}^{5}{f\left( x \right)\text{d}x}\Rightarrow \int\limits_{2}^{5}{f\left( x \right)\text{d}x}=\int\limits_{0}^{5}{f\left( x \right)\text{d}x}-\int\limits_{0}^{2}{f\left( x \right)\text{d}x}=6-3=3$
Đáp án B.