$\frac{x\cdot x+\frac{1}{x\cdot x}}{x\cdot x\cdot x+\frac{1}{x\cdot x\cdot x}}$

$\cos\left(x\right)\left(1-cos^2\left(x\right)\right)$

$\sqrt[3]{81z^4x^6y^5}$

$-\sqrt{11}+4\:\sqrt{11}-7\sqrt{11}$

$\int\left(x^2+1\right)x^2dx$

$\int\:\frac{e^x}{361-e^{2x}}dx$

$x^2-10x+21<0$