$f\left(x\right)=-2x^4+5x^3-x$

$\lim_{x\to-9}\left(\frac{2\sqrt{x-6}}{x-9}\right)$

$\frac{\frac{a}{b}-2+\frac{b}{a}}{\frac{a}{b}-\frac{b}{a}}$

$\frac{d}{dx}\left(\frac{x^3\sqrt{x^2+1}}{\left(3x-1\right)^2}\right)$

$\left(z^4+6\right)^5$

$sin\left(3.5\right)$

$\int\frac{x+4}{x^3+3x+2x}dx$