$\frac{\sec^2\theta}{\tan^2\theta}$

$\frac{y^9\left(y^3x^{-2}\right)^{-3}}{\left(5y^2\right)^4x^2}$

$4x^2-2y^2dx=2xydy$

$2.5+11.5$

$a^4-10a^2+25$

$\frac{dy}{dx}=\frac{ycos\left(x\right)}{2y-1}$

$\frac{\sin^2\left(\frac{1}{2}\pi\right)}{tan^2\left(\frac{1}{2}\pi\right)}$