$\frac{\cos\left(4x\right)-\cos\left(12x\right)}{\sin\left(12x\right)+\sin\left(4x\right)}=\tan\left(4x\right)$

$\:ixi\le7$

$\lim_{x\to\infty}\left(\ln\left(n\right)\right)^2$

$\frac{dy}{dx}+y=100$

$81x^2y^2-6az^2$

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

$\left(-2x^2+3y^2-1\right)\:\left(6x^3-2y^3\right)$