$\left(\cos x-2\right)\left(\sin x+2\right)=0$

$\int e^x\sqrt{1-e^x}dx$

$\int_r^{3r}\frac{8}{r^3}dr$

$\csc^22b-2\csc b-3$

$\frac{5\left(-3-4\right)-\left(-6\right)\left(13-6\right)}{\left(-1\right)\left(11-4\right)}$

$\int\left(\frac{\ln\left(\sqrt{x}\right)}{x^2}\right)dx$

$\frac{x^3}{1-2x^2}$