integral [1 to 2] (lnx)^2/(x^3)
how would i solve this
$\displaystyle \int \frac{(ln(x))^2}{x^3}dx$
When I see a ln(x) and an x in the denominator, the first thing I think of is to substitute u= ln(x). Then $\displaystyle du= \frac{1}{x} dx$. In this problem that still leaves $\displaystyle x^2$ in the denominator but if u= ln(x), then $\displaystyle x= e^u$ and $\displaystyle \frac{1}{x^2}= e^{-2u}$.
The integral becomes $\displaystyle \int ue^{-2u}du$ which can be done by integration by parts.