Quiz 2:口訣快解
求不定積分 \(\int {\frac{{2x + 3}}{{{x^2} + 3x}}\;dx} \)
\(\ln ({x^2} + 3x) + C\)
\(2\ln (x + 3) + C\)
\(\ln (2x + 3) + C\)
\(\ln ({x^2} + 3) + C\)