$seca\left(\cos a+cota\right)$

$\lim_{x\to5}\left(4\left(x-5\right)\right)^{x-5}$

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

$1002\cdot998$

$\int_{0.5}^{2.5}\left(\frac{3}{\sqrt{3x-x^2}}\right)dx$

$x^2yz+3xy^2-2xyz^2-3xy^2z+xyz^2-x^2yz$

$\left(m+2n\right)^2-\left(m-n\right)^2$