Evaluate the following integrals:

Evaluate the following integrals:

(i) $\left(\frac{1-\cos 2 x}{1+\cos 2 x}\right) d x$

(ii) $\left(\frac{1+\cos 2 \mathrm{x}}{1-\cos 2 \mathrm{x}}\right) \mathrm{dx}$