Question Number 157803 by cortano last updated on 28/Oct/21
$$\:\:\underset{{x}\rightarrow\mathrm{0}} {\mathrm{lim}}\:\frac{{x}\:\mathrm{tan}\:\left(\mathrm{tan}\:{x}\right)−\left(\mathrm{tan}\:{x}\right)^{\mathrm{2}} }{{x}^{\mathrm{6}} }\:=? \\ $$