$\int4ay^{3\:}dy$

$3y\frac{dy}{dx}=3x$

$6x^2-21x+12=0$

$\tan\left(x\right)\cdot\cot\left(x\right)-\sin^2x$

$\lim_{x\to0}\left(\frac{2x^2-3x+1}{ln\left(x\right)}\right)$

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

$\frac{d^2}{dx^2}\left(sin\left(\frac{1}{2}x\right)\right)$