Nếu ln 3 ∫ 0 [ f ( x ) + e x ] d x = 6 thì ln 3 ∫ 0 f ( x ) d x bằng

19/55

Nếu \(\int\limits_0^{\ln 3} {\left[ {f\left( x \right) + {e^x}} \right]{\rm{d}}x} = 6\)thì \[\int\limits_0^{\ln 3} {f\left( x \right){\rm{d}}x} \]bằng

\[6 + \ln 3\].

\[6 - \ln 3\].

\(4\).

\(8\).

Giải thích

Chọn C

Ta có: \(\int\limits_0^{\ln 3} {\left[ {f\left( x \right) + {e^x}} \right]{\rm{d}}x} = \int\limits_0^{\ln 3} {f\left( x \right){\rm{d}}x} + \int\limits_0^{\ln 3} {{e^x}{\rm{d}}x} = \int\limits_0^{\ln 3} {f\left( x \right){\rm{d}}x} + 2\)

Suy ra \(\int\limits_0^{\ln 3} {f\left( x \right){\rm{d}}x} = 6 - 2 = 4\).