$$\lim_{x \to \infty}\left(\cos{\left(x \right)} \cos{\left(2 x \right)}\right) = \left\langle -1, 1\right\rangle$$
$$\lim_{x \to 0^-}\left(\cos{\left(x \right)} \cos{\left(2 x \right)}\right) = 1$$
More at x→0 from the left$$\lim_{x \to 0^+}\left(\cos{\left(x \right)} \cos{\left(2 x \right)}\right) = 1$$
More at x→0 from the right$$\lim_{x \to 1^-}\left(\cos{\left(x \right)} \cos{\left(2 x \right)}\right) = \cos{\left(1 \right)} \cos{\left(2 \right)}$$
More at x→1 from the left$$\lim_{x \to 1^+}\left(\cos{\left(x \right)} \cos{\left(2 x \right)}\right) = \cos{\left(1 \right)} \cos{\left(2 \right)}$$
More at x→1 from the right$$\lim_{x \to -\infty}\left(\cos{\left(x \right)} \cos{\left(2 x \right)}\right) = \left\langle -1, 1\right\rangle$$
More at x→-oo