$w-5w-8$

$\frac{1}{b-1}=\frac{2}{b-2}$

$\left(1+cos\theta\:\right)\left(1-cos\theta\:\right)=sin\theta\:\:cos\theta\:\:tan\theta\:$

$\int\cot^5axdx$

$\left(-9x^2+2\right)+\left(4x^2-9x\right)$

$\frac{dy}{dx}+\frac{1}{2}sec\left(\frac{t}{2}\right)=3cos\left(\frac{t}{2}\right)$

$\lim_{x\to0}\left(\frac{\sin x}{x}\right)\left(x\right)$