$\sec^2\left(x\right)-2\sec\left(x\right)=15$

$\lim_{z\to k}\left(\frac{\left(z-k\right)\pi\cot\left(\pi z\right)}{z^2}\right)$

$\lim_{x\to\infty}\left(x^3-e^x\right)$

$\lim_{x\to0}\left(\frac{e^{4t}-1}{2t}\right)$

$-\left(-7v+\:6\right)$

$\int8\cdot x^2\cdot e^{12\cdot x}dx$

$x^3+216$