$\lim_{x\to3}\left(\frac{x^2}{1-cos\left(x\right)}\right)$

$\left(x+7\right)\left(x-9\right)$

$\int_{3x}^{3x^2}\left(\frac{3t+5}{2t-2}\right)dt$

$\int5sin^2\left(x\right)dx$

$\frac{15x^5-11x^4+21x^3-x^2+3}{3x^2-x+2}$

$\left(1-x\right)^3$

$\left(1+\frac{3}{x}\right)^{\frac{1}{2}}$