$\lim_{x\to\frac{\pi}{2}}\left(\frac{cos\left(x\right)}{x-\frac{\pi}{2}}\right)$

$\frac{\cos^2\left(x\right)+1}{sin^2\left(x\right)}-19$

$\lim_{x\to\infty}\frac{2x+1}{4x^2+x}$

$3+2+7+5+8+10+11+4+3$

$\left(1-\frac{3}{\:y}+x\right)dy+\left(y-\frac{3}{x}+1\right)dx=0$

$\left(\frac{1}{2}y\right)^2$

$\ln\left(x+3\right)=2$