$-27:-3$

$\lim_{x\to\infty}\left(\frac{\arctan\left(x^6\right)}{x^8}\right)$

$2x-3<3x-6$

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

$\frac{\cos\left(x\right)}{1-\tan\left(x\right)}-\frac{\sin\left(x\right)}{\cot\left(x\right)-1}$

$\int_3^4\left(\frac{3}{\sqrt{4x-x^2}}\right)dx$

$450x\frac{4}{5}$