Câu hỏi: Giá trị thực lớn hơn 1 của tham số m thỏa mãn $\int\limits_{1}^{m}{{{\ln }^{2}}xdx}=m.\ln m\left( \ln m-2 \right)+{{2}^{1000}}$ là
A. $m={{2}^{1000}}$.
B. $m={{2}^{1000}}+1$.
C. $m={{2}^{999}}+1$.
D. $m={{2}^{999}}+2$.
A. $m={{2}^{1000}}$.
B. $m={{2}^{1000}}+1$.
C. $m={{2}^{999}}+1$.
D. $m={{2}^{999}}+2$.
Đặt $\left\{ \begin{aligned}
& u={{\ln }^{2}}x \\
& dv=dx \\
\end{aligned} \right.\Rightarrow \left\{ \begin{aligned}
& du=\dfrac{2\ln x}{x}dx \\
& v=x \\
\end{aligned} \right.$
Khi đó $I=x.{{\ln }^{2}}x\left| \begin{aligned}
& m \\
& 1 \\
\end{aligned} \right.-2\int\limits_{1}^{m}{\ln xdx}=m.{{\ln }^{2}}m-2\int\limits_{1}^{m}{\ln xdx}=m.{{\ln }^{2}}m-2J$.
Đặt $\left\{ \begin{aligned}
& u=\ln x \\
& dv=dx \\
\end{aligned} \right.\Rightarrow \left\{ \begin{aligned}
& du=\dfrac{1}{x}dx \\
& v=x \\
\end{aligned} \right.\Rightarrow J=x.\ln x\left| \begin{aligned}
& m \\
& 1 \\
\end{aligned} \right.-\int\limits_{1}^{m}{dx}=m.\ln m-\left( m-1 \right)$
Suy ra $I=m.{{\ln }^{2}}m-2m.\ln m+2\left( m-1 \right)=m.\ln m\left( \ln m-2 \right)+2\left( m-1 \right)$.
Theo bài ra ta có $\int\limits_{1}^{m}{{{\ln }^{2}}xdx}=m.\ln m\left( \ln m-2 \right)+{{2}^{1000}}$
$\Rightarrow m.\ln m\left( \ln m-2 \right)+2\left( m-1 \right)=m.\ln m\left( \ln m-2 \right)+{{2}^{1000}}$
$\Leftrightarrow 2\left( m-1 \right)={{2}^{1000}}\Leftrightarrow m-1={{2}^{999}}\Leftrightarrow m={{2}^{999}}+1$.
& u={{\ln }^{2}}x \\
& dv=dx \\
\end{aligned} \right.\Rightarrow \left\{ \begin{aligned}
& du=\dfrac{2\ln x}{x}dx \\
& v=x \\
\end{aligned} \right.$
Khi đó $I=x.{{\ln }^{2}}x\left| \begin{aligned}
& m \\
& 1 \\
\end{aligned} \right.-2\int\limits_{1}^{m}{\ln xdx}=m.{{\ln }^{2}}m-2\int\limits_{1}^{m}{\ln xdx}=m.{{\ln }^{2}}m-2J$.
Đặt $\left\{ \begin{aligned}
& u=\ln x \\
& dv=dx \\
\end{aligned} \right.\Rightarrow \left\{ \begin{aligned}
& du=\dfrac{1}{x}dx \\
& v=x \\
\end{aligned} \right.\Rightarrow J=x.\ln x\left| \begin{aligned}
& m \\
& 1 \\
\end{aligned} \right.-\int\limits_{1}^{m}{dx}=m.\ln m-\left( m-1 \right)$
Suy ra $I=m.{{\ln }^{2}}m-2m.\ln m+2\left( m-1 \right)=m.\ln m\left( \ln m-2 \right)+2\left( m-1 \right)$.
Theo bài ra ta có $\int\limits_{1}^{m}{{{\ln }^{2}}xdx}=m.\ln m\left( \ln m-2 \right)+{{2}^{1000}}$
$\Rightarrow m.\ln m\left( \ln m-2 \right)+2\left( m-1 \right)=m.\ln m\left( \ln m-2 \right)+{{2}^{1000}}$
$\Leftrightarrow 2\left( m-1 \right)={{2}^{1000}}\Leftrightarrow m-1={{2}^{999}}\Leftrightarrow m={{2}^{999}}+1$.
Đáp án C.