$\left(1.96\right)^2\cdot0.5\cdot0.5$

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

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

$\frac{x^{14}+1}{x^2+1}$

$-20\cdot23$

$\lim_{x\to0}\frac{\sin^2\left(\frac{x}{2}\right)}{5x}$

$\frac{cos\left(x\right)+1}{\cos\left(x\right)-1}=\frac{1+sec\left(x\right)}{1-sec\left(x\right)}$