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#### paulmdrdo

##### Active member
can someone give me hints how to solve this.

$\displaystyle \int\frac{ln^2\,3x}{x}dx$

#### Sudharaka

##### Well-known member
MHB Math Helper
can someone give me hints how to solve this.

$\displaystyle \int\frac{ln^2\,3x}{x}dx$
Hi paulmdrdo,

Substitute $$u=\ln(3x)$$.

#### topsquark

##### Well-known member
MHB Math Helper
can someone give me hints how to solve this.

$\displaystyle \int\frac{ln^2\,3x}{x}dx$
To add to Sudharaka's sage suggestion, whenever you have a ln in numerator and x in the denominator of the integrand, some kind of u = ln(x) substitution bears looking into.

-Dan