$\int\frac{1}{\left(t^2+9\right)^2}dt$

$\lim_{x\to0}\left(ln\left(x\right)^{-x}\right)$

$\lim_{x\to\infty}\left(\frac{\left|x-c\right|}{2x-2c}\right)$

$\frac{d}{dx}\sec^{-1}x^4$

$\int\left(x\cdot\left(ln\left(x\right)+5\right)\right)dx$

$-1150+370-1389$

$10\:cm\:b\:20cm\:\sqrt{300}$