$a^4b^2b^7$

$\frac{18x^3}{9+x^2}$

$\lim_{x\to0}\left(\cos\left(\frac{16}{x}\right)\right)^{x^2}$

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

$\int_1^2e^x\sin\left(x\right)dx$

$\frac{\sec-1}{\tan^2}$

$\lim_{x\to\infty}\left(\frac{7x^4-x^3+3}{4x^5+x^2+4}\right)$