$\frac{1}{\left(1-z^{-1}\right)\left(1-0.5z^{-1}\right)}$

$\frac{\left(1+cot^2\left(x\right)\right)}{sec^2\left(x\right)}+cos^2\left(x\right)+\left(\frac{1}{csc^2\left(x\right)}\right)$

$2^1\cdot2^{-3}$

$-\sin\left(a\right)-\sin\left(b\right)$

$2x\left(3x-4\right)$

$12.4\cdot6.2$

$\frac{dy}{dx}=-8x$