Find the limit when $x$ approaches zero of $$\lim\limits_{x \to 0}{\frac{1-\cos(1-\cos x)}{x^4}}$$
My teacher already told us that the result is $1/8$
Find the limit when $x$ approaches zero of $$\lim\limits_{x \to 0}{\frac{1-\cos(1-\cos x)}{x^4}}$$
My teacher already told us that the result is $1/8$