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

$\lim_{x\to0}\left(\frac{2-e^x-e^{-x}}{sin^2\left(x\right)}\right)$

$\lim_{t\to\infty}\:\left[tln\left(\frac{3}{t}\right)\right]$

$64b^4-36a^2$

$\:45.27-1.27$

$2\cdot3^2+2\cdot5-12$

$\int a\left(x+y\right)e^{-\left(x+y\right)}dx$