$\frac{\cos\left(2x\right)}{2}$

$\frac{4}{\sqrt{1-x^2}}$

$\lim_{x\to0}\left(\frac{\ln\left(x^2+1\right)}{x^2+x}\right)$

$\frac{6n+3}{\frac{n-6}{2}}=\frac{6n-22}{\frac{n-8}{2}}$

$\left(4x^3+6x^2-8x+1\right)+\left(2x^2+7x-7\right)$

$cos\left(2a\right)=0.8078$

$2\left(x+y\right)+\left(y+x\right)=310$