$2\cot\left(x\right)\cot\left(2x\right)=\cot^2\left(x\right)+1$

$x-3\le4$

$\int3x^6e^xdx$

$\int\left(\frac{\left(e^x+\sin\left(x\right)\right)}{\left(e^x-\cos\left(x\right)\right)}\right)dx$

$x-3+x+2$

$\frac{d}{dx}\left(x+6\right)\left(x+4\right)\left(x+9\right)\left(x+2\right)$

$\left(xy\right)^0$