$\frac{sin\left(x\right)}{1-cos\left(x\right)}-\frac{sin\left(x\right)}{1+cos\left(x\right)}=cot\left(x\right)$

$\int\left(\frac{4}{\left(1-2x\right)^6}\right)dx$

$5ab^5-2a^5b-8ab^5+9a^5b$

$\frac{1}{\cos\left(a\right)\sin\left(a\right)}=\frac{2}{\sin\left(2a\right)}$

$\lim_{x\to\frac{-\pi}{4}}\frac{\left(\tan\left(x\right)+1\right)}{4x+\pi}$

$10x^2-13x-3$

$\frac{5^2-7^2}{2\cdot2-12}$