Google
Câu hỏi: Cho $\int\limits_{a}^{d}{f\left( x \right)\text{d}x}=5$, $\int\limits_{b}^{d}{f\left( x \right)\text{d}x}=2$ với $a<d<b$. Tính $I=\int\limits_{a}^{b}{f\left( x \right)\text{d}x}$.
A. $I=3$.
B. $I=-3$.
C. $I=7.$.
D. $I=0$.
Ta có $I=\int\limits_{a}^{b}{f\left( x \right)\text{d}x}=\int\limits_{a}^{d}{f\left( x \right)\text{d}x}+\int\limits_{d}^{b}{f\left( x \right)\text{d}x}$ $=\int\limits_{a}^{d}{f\left( x \right)\text{d}x}-\int\limits_{b}^{d}{f\left( x \right)\text{d}x}$ $=5-2=3$.
A. $I=3$.
B. $I=-3$.
C. $I=7.$.
D. $I=0$.
Ta có $I=\int\limits_{a}^{b}{f\left( x \right)\text{d}x}=\int\limits_{a}^{d}{f\left( x \right)\text{d}x}+\int\limits_{d}^{b}{f\left( x \right)\text{d}x}$ $=\int\limits_{a}^{d}{f\left( x \right)\text{d}x}-\int\limits_{b}^{d}{f\left( x \right)\text{d}x}$ $=5-2=3$.
Đáp án A.