Originally Posted by

**Craka** Man I'm having problems.

Question is

$\displaystyle \int_1^2 {(\ln (x))^2 } dx \\ $

I get this

$\displaystyle = \int_1^2 {\ln (x)\ln (x)dx} \\ $

$\displaystyle = \frac{1}{x}\ln (x) - \int {\frac{1}{x}} \times \frac{1}{x}dx \\ $

$\displaystyle = \frac{1}{x}\ln (x) - \int {x^{ - 2} } dx \\$

$\displaystyle = \frac{1}{x}\ln (x) - [ - x^{ - 1} ] \\ $

$\displaystyle = \frac{1}{x}\ln (x) + \frac{1}{x} \\ $

$\displaystyle = [\frac{1}{2}\ln (2) + \frac{1}{2}] - [\frac{1}{1}\ln (1) + \frac{1}{1}] \\$

$\displaystyle = \frac{1}{2}\ln (2) - \frac{1}{2} \\

$

But apparently it should be

$\displaystyle = 2(\ln (2))^2 - 4\ln (2) + 2

$