Cho nguyen ham (-1)^2 f(x)dx=2 và nguyen ham (-1)^2 g(x)dx=-1. Tính I=nguyen ham (-1

* Hướng dẫn giải

Chọn D.

Ta có: $\mathrm{I}={\int }_{-1}^2\mathrm{xdx}+{\int }_{-1}^{2}2\mathrm{f}\left(\mathrm{x}\right)\mathrm{dx}+{\int }_{-1}^{2}3\mathrm{g}\left(\mathrm{x}\right)\mathrm{dx}$

$= \frac{{\mathrm{x}}^2}{2}{|}_{-1}^2+2{\int }_{-1}^2\mathrm{f}\left(\mathrm{x}\right)\mathrm{dx}+3{\int }_{-1}^2\mathrm{g}\left(\mathrm{x}\right)\mathrm{dx}=\frac{5}{2}.$