$\frac { 2 + 2 } { 4 }$

$4cos^2x+cosx-5$

$\lim_{x\to1}\left(\frac{x^2-3x+2}{x^2+1}\right)$

$-196+\frac{4}{25}h^2v^2$

$\ln\left(2x+15\right)-\ln\left(x\right)=\ln\left(3\right)$

$g\left(x\right)=\frac{\left(5x^2+x+2\right)}{\left(x+1\right)\left(x^2+1\right)}$

$tgx\left(1-ctgx\right)+ctgx\left(1-tg^2x\right)+\left(1-cos^2x\right)$