If $I_1=\int\limits_{e}^{e^2}\frac{dx}{\log x}$ and $I_2=\int\limits_{1}^{2}\frac{e^x}{x}dx$, then
Answer & explanation
Correct answer: option 1
$I_2=\int\limits_{1}^{2}\frac{e^x}{x}dx$
let $y=e^x⇒dy=e^xdx$
so $x=\log y$
as $x → 1, y → e$
$x → 2, y → e^2$
$I_2=\int\limits_{e}^{e^2}\frac{dy}{\log y}$
$⇒I_2=\int\limits_{e}^{e^2}\frac{dx}{\log x}=I_1$