Cho \(\displaystyle\int\limits^1_0f(x)\mathrm{\,d}x=-3\) và \(\displaystyle\int\limits^1_0g(x)\mathrm{\,d}x=2\). Khi đó \(\displaystyle\int\limits^1_0\left[f(x)+2g(x)\right]\mathrm{\,d}x\) bằng
| \(1\) | |
| \(-1\) | |
| \(-7\) | |
| \(5\) |
Chọn phương án A.
\(\begin{align*}\displaystyle\int\limits^1_0 \left[ f(x)+2g(x)\right]\mathrm{\,d}x&=\displaystyle\int\limits^1_0f(x)\mathrm{\,d}x+2\displaystyle\int\limits^1_0g(x)\mathrm{\,d}x\\
&=-3+2\cdot 2=1.\end{align*}\)