$x\frac{\pi}{3}\:\frac{\sin\left(x\right)}{\sin\left(x\right)+\cos2\left(x\right)}$

$\frac{\sec\left(x\right)}{\left(1-2\sec^2\left(x\right)\right)}$

$\frac{1-\cos^2x}{\sec^2x-1}=\cos^2x$

$\left(2a-3b+a^2\right)^2$

$\left(3x+y\right)\cdot\left(3x-y\right)$

$\int\frac{lnx+2}{x\sqrt{-9lnx^2+6lnx+3}}dx$

$-3\left(-2\right)\left(-1\right)$