$\lim_{x\to e}\left(\frac{19\ln x-9}{x-e}\right)$

$\int4\tan^3\left(x\right)dx$

$\frac{6}{14},\:\frac{9}{21}$

$\sin y\cdot\cos\left(x\right)-\left(\sin\left(y\right)\cdot\cos\left(x\right)\right)$

$\lim_{x\to\infty}\left(\frac{6x-1}{\sqrt{x^2+5}}\right)$

$\frac{dy}{dx}=\frac{x}{2y-4}$

$\left(2x^2+7\right)^2$