$\frac{\sec a}{\sin a}-\frac{\sin a}{\cos a}=\cot a$

$\frac{dy}{dx}=\frac{\left(x^2+1\right)}{\left(4xy\right)}$

$\int\left(\frac{4x}{x^2-1}\right)dx$

$\left(x^3-8\right)\left(x^3+12\right)$

$\left(2mn^2\right)\left(3m^{-1}n^{-3}\right)$

$1^2+1^2-2\:x\:1\:$

$6a^3-5a^3+8a^3-3a^3+12a^3-4a^3+2a^30$