$-\left[3-\left(8-6\right)-\left(5+4\right)\right]$

$\lim_{x\to\pi}\:sin\left(2x\right)csc\left(4x\right)$

$\int\:\frac{x^5}{1+x^3}dx$

$\lim_{x\to\infty}\left(\frac{4x^2-2x+1}{\sqrt{3x^4-3x^3+1}}\right)$

$2x^4-3x^3-9x^2+4$

$\left(-2\right)-\left(-10\right)$