$1-3-\left(5-7+4\right)-\left(1-2\right)$

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

$\int\left(\frac{x^3}{\sqrt{\left(4-x^2\right)}}\right)dx$

$6-5\left(1-2\cdot3+4\cdot2\right)$

$( 5 x ^ { \frac { 1 } { 2 } } ) ^ { 2 }$

$\lim_{x\to\infty}e^{e^2}$

$\frac{a^2}{4}-b^6$