Lim {{5^{2x}} - 6{e^{ -{x} / {2){d}}x} \] bằng:
Giải thích
Ta có \[\int {\left( {{5^{2x}} - 6{{\rm{e}}^{ - \frac{x}{2}}}} \right){\rm{d}}x} = \int {{{25}^x}{\rm{d}}x} - 6\int {{{\left( {{{\rm{e}}^{ - \frac{1}{2}}}} \right)}^x}dx} \]
\[ = \frac{{{{25}^x}}}{{\ln 25}} - 6\frac{{{{\rm{e}}^{ - \frac{x}{2}}}}}{{\ln {e^{ - \frac{1}{2}}}}} + C = \frac{{{{25}^x}}}{{2\ln 5}} + 12{{\rm{e}}^{ - \frac{x}{2}}} + C\].Chọn B.