$9t^2-36t+144$

$\frac{\sec\left(a\right)}{\cot\left(a\right)}$

$\lim_{x\to3}\left(3x^2-7x+5\right)$

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

$\left(x^3\:+\:7\right)\:\left(x^5\:-\:2x^4\:+\:5x^3\:+\:x^2\:-\:3x\:+\:1\right)\:$

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

$\lim_{x\to\infty}\left(\frac{4x^3+2}{x^2+20x}\right)$