$\left(4x^4+3x^3+2x^2+1\right)+\left(5x^4-2x+3\right)$

$x+1>x^2-1$

$\frac{d}{dx}3x^2\:+\:\frac{3}{7}xy\:-\:5y^2\:\:=\:1$

$\lim\:_{x\to\:0\:}e^{\frac{sin\left(5x\right)}{3x}}$

$x^4+12x^3-64x^2=0$

$\tan\left(a\right)=\frac{1}{2}$

$\lim_{x\to0}\left(\frac{x^3+\cos\left(x\right)-1}{5e^x+4x-5}\right)$