$\frac{x^6-b^6}{x^2-b^2}$

$\lim_{x\to0}\left(\frac{sin\left(5x\right)}{1-cos\left(3x\right)}\right)$

$\frac{du}{dx}=2-u$

$b\left(x^3-6x^2+12x-8\right)$

$\frac{sec^2\left(\frac{\pi}{2}\right)}{3sec^2\left(\frac{3\pi}{2}\right)}$

$y'=-16y$

$\int3\left(x^2\ln\left(x\right)\right)dx$