$\:b\:4\:-b\:3\:$

$\frac{\left(2sec\left(t\right)\right)}{\left(5\left(tan\left(t\right)sin\left(t\right)+cos\left(t\right)\right)\right)}$

$\int\frac{x+12}{x^2-x-6}dx$

$\lim_{x\to\infty}\left(xlnx^{4400}\right)$

$0.000003x^2-0.04x+200-\frac{70000}{x}$

$\int_1^{\sin\left(a\right)}\left(\sqrt{1-u^2}\right)du$

$3x^2\left(5x-6x^3\right)$