\(\displaystyle \lim_{x \to 0}\frac{x}{x-\tan x}\left ( =\frac 00 \right )\overset{H}{=}\displaystyle \lim_{x \to 0}\frac{1}{1-\frac{1}{\cos^2 x}}=\frac{1}{-0}=-\infty\)
\(\displaystyle \lim_{x \to 0}\frac{1}{1-\cos x}=\frac{1}{+0}=+\infty\)
gricha - v6986 - 31.5.12