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

$10-\left(-5-6\right)+10-\left(10+1\right)$

$\cos\left(2x\right)+2\cos^2x=0$

$\frac{dy}{dx}=y-\frac{y^2}{9}-\frac{8}{9}$

$c-3+2x-6c+4x$

$\frac{1}{\frac{1}{5}}$

$\int\left(x^3+3\right)\cdot2x^2dx$