$\int_{-n}^n\left(n^2-x^2\right)dx$

$\frac{18}{6}+\left(8\cdot3+\left(5+2\cdot5\right)\right)-\left(3\cdot6-4+2^3\right)$

$x^2-9x+4$

$\int\frac{2x-19}{x^2+x-6}dx$

$\left[10-\left(-2\right)\right]-\left[5-\left(12\right)\right]+\left[1+\left(6-9\right)\right]$

$\lim_{x\to0}\:\left(4x^3-7x^2+4x-1\right)$

$cos^2\left(2x\right)=\frac{1+cos\left(4x\right)}{2}$