$\frac{dy}{dx}=-x\frac{e^{-x^2}}{y}$

$-6x+3\le-8x-7$

$x^2-22x-48$

$\sin^21.01+\cos^21.01$

$\lim_{x\to9}\left(\frac{\frac{1}{x}-\frac{1}{9}}{d-9}\right)$

$\int_{1}^{e}\frac{\left(\ln\left(2x\right)\right)^{3}}{x}dx$

$\frac{1-tan^2\left(a\right)}{1+tan^2\left(a\right)}=2cos^2\left(a\right)-1$