$1-tan\left(x\right)=\frac{cos\left(x\right)}{cos\left(x\right)}+\frac{-sin\left(x\right)}{cos\left(x\right)}$

$\frac{1}{\left(x+5\right)\left(x^2\right)}$

$\int_0^{\pi}\left(\left(1-\cos\left(x\right)\right)\sin\left(x\right)\right)dx$

$\int\frac{x}{3}+\frac{3}{x}.dx$

$\left(6g+8\right)\left(6g-8\right)$

$4k\cdot9k^3$

$\lim_{x\to\infty}\left(\frac{cos\left(x\right)+3x-1}{5x}\right)$