$x-4<-1$

$4x^2+10x-6$

$\frac{3}{4}x+2+x$

$\int\left(\frac{e^x}{1-e^{2x}}\right)dx$

$\frac{cos^2x}{1-sinx}=\frac{\left(cscx+1\right)}{cscx}$

$\lim_{x\to1}\left(\frac{1-\cos\left(x-1\right)}{1-x\:\tan\left(x-1\right)}\right)$

$\lim_{x\to0}\left(\frac{\left(\sqrt{x}-x\right)\arcsin\left(x\right)}{x}\right)$