Hi

Can someone tell me why this is incorrect.

$\displaystyle \int sin^2(x)cos^2(x)dx$

$\displaystyle \int (0.5(1-cos(2x))(0.5(cos(2x)+1))dx$

$\displaystyle \int (0.5-\frac{cos(2x)}{2})(\frac{cos(2x)}{2}+0.5))dx$

$\displaystyle \int \frac{1}{4} - \frac{cos^2(x)}{4} dx$

$\displaystyle \frac{1}{4} \int dx - \frac{1}{4} \int cos^2(2x)$

$\displaystyle u=cos(2x)$

$\displaystyle du=-sin(2x)$

$\displaystyle \frac{x}{4} - \frac{1}{4} \int u^2 du$

$\displaystyle \frac{x}{4} - \frac{1}{4} * \frac{u^3}{3} +c$

$\displaystyle \frac{x}{4} - \frac{1}{4} * \frac{cos^3(2x)}{12} +c$

P.S