$\frac{1-\cos\:^2\left(\theta\:\right)}{1-\sin\:^2\left(\theta\:\right)}$

$x\left(\sqrt{1+v^2}\right)dx=x^2dv$

$\frac{dy}{dx}+\frac{cos\left(x\right)}{\sin\left(x\right)}y=\frac{1}{\sin\left(x\right)}$

$24=y+19$

$3a\cdot4a^3$

$-1-\left[5-\left(-2\right)\right]$

$2sin\left(\frac{1}{5}\right)x=-\sqrt{3}$