$\int\frac{1}{x^3\left(x-1\right)^2}dx$

$1a$

$a+\frac{1}{b}=1$

$\frac{\left(\left[-\left\{\left(85\left(-0.25\right)+85\right)-\frac{1}{2}\right\}+\left\{-\left(85\left(-0.25\right)+85\right)\right\}-\frac{1}{2}\right]^3-3\pi\right)-\left(-3\pi+\frac{5}{2}\right)}{\frac{19}{\frac{2}{78}}}$

$\frac{sin2x}{1-cos2x}=tanx$

$\lim_{x\to\infty}\left(\left(x\cdot\:\left(\sqrt{\left(x+1\right)}-x\right)\right)\right)$

$\frac{d}{dx}\:2x^2-3y^2=4$