$\cos\left(x\right)\sec\left(y\right)$

$\left(\cos\left(x\right)\cos\left(y\right)-\cot\left(x\right)\right)dx-\left(\sin\left(x\right)\sin\left(y\right)\right)dy=0$

$\int\frac{x+9}{3x^2-x-10}dx$

$y'=\:1\:+\:y$

$3x+2<\frac{7x}{2}$

$\frac{dy}{dx}=\frac{1}{\left(x^2+1\right)}$

$\left(4x+3\right)\le x$