$\lim_{x\to0}\left(\frac{\frac{1}{\sqrt{a+x+7}}-\frac{1}{\sqrt{a+7}}}{x}\right)$

$\left(1+\tan^2\left(5\right)\right)\cos^2\left(5\right)$

$x^2+18x+c=25+c$

$\int\sqrt[3]{\sqrt{x^5}}dx$

$-8\left(-3\right)\left(-1\right)\:\left(2\right)$

$\int\frac{x-2}{\left(x^2+4x+13\right)}dx$

$\int_{-\infty\:}^0\left(\frac{lnx}{x^2}\right)dx$