$\left(2+4a\right)^2$

$\lim_{x\to0}\left(\frac{x^{2}\cdot\ar+12}{x-6}\right)$

$\lim_{x\to+\infty}\left(\frac{6x}{\ln\left(x\right)+3x}\right)$

$\left(\tan\left(a\right)^2-sec\left(a\right)^2\right)\left(sin\left(a\right)^2-\cos\left(a\right)^2\right)$

$\int cot^22xcsc^22xdx$

$\int\frac{5x^2-9x-4}{\left(x-1\right)\left(x^2+4\right)}dx$

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