Limit x Tends to Zero (1-cos2x)/3 tan^2x
$\lim_{x\rightarrow 0}\frac{1 – cos2x}{3tan^2x}$
= $\lim_{x\rightarrow 0}\frac{\cos^2x + sin^2x – (cos^2x – sin^2x)}{3tan^2x}$
= $\lim_{x\rightarrow 0}\frac{\cos^2x + sin^2x – cos^2x + sin^2x}{3tan^2x}$
= $\lim_{x\rightarrow 0}\frac{2sin^2x}{3tan^2x}$
= $\lim_{x\rightarrow 0}\frac{2sin^2x}{3\frac{\sin^2x}{\cos^2x}}$
=$ \lim_{x\rightarrow 0}\frac{2sin^2xcos^2x}{3sin^2x}$
= $\frac{2}{3}\lim_{x\rightarrow 0}\cos^2x $
= $\frac{2}{3}$