Răspuns:
Explicație pas cu pas:
[tex]\displaystyle\ln x=\begin{cases}0,x\in[1,e)\\1,x\in[e,e^2)\\2,x\in[e^2,9]\end{cases}\\\texttt{Prin urmare:}\\I=\int_e^{e^2}\dfrac{1}{x}dx+\int_{e^2}^9\dfrac{2}{x}dx=\ln x|_e^{e^2}+2\ln x|^9_{e^2}=\ln e^2-\ln e+2\ln 9-2\ln e^2=\\=2-1+2\ln 9-4=2\ln 9-1\\\texttt{Raspunsul corect este }\bold{b)}[/tex]
