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Câu hỏi: Nếu $\int\limits_{0}^{4}{f\left( x \right)\text{d}x=5}$ và $\int\limits_{2}^{4}{f\left( x \right)\text{d}x=-1}$ thì $\int\limits_{0}^{2}{f\left( x \right)\text{d}x}$ bằng
A. $6$.
B. $4$.
C. $-4$.
D. $-6$.
A. $6$.
B. $4$.
C. $-4$.
D. $-6$.
Ta có $\int\limits_{0}^{4}{f\left( x \right)\text{d}x=}\int\limits_{0}^{2}{f\left( x \right)\text{d}x+\int\limits_{2}^{4}{f\left( x \right)\text{d}x\Leftrightarrow }}\int\limits_{0}^{2}{f\left( x \right)\text{d}x=}\int\limits_{0}^{4}{f\left( x \right)\text{d}x-\int\limits_{2}^{4}{f\left( x \right)\text{d}x=}5-\left( -1 \right)=6}$.
Đáp án A.