$\left(x+\sqrt{y}\right)\left(x+\sqrt{y}\right)$

$\left(-\sqrt{3}\right)\cdot\left(-\sqrt{3}\right)$

$x\left(x-2\right)\ge\:3$

$\lim_{x\to-\infty\:}\left(\frac{x^3-1}{-x^2+3x-2}\right)$

$\frac{dy}{dx}\left(x\ln y+y^2=7\ln x\right)$

$\frac{\cot x}{\sec x+1}$

$xy\cdot x^2y^3\cdot x^3y^4$