The set of all values of $\lambda$ for which the equation $\cos ^2 2 x-2 \sin ^4 x-2 \cos ^2 x=\lambda$
$[-2,-1]$
$\left[-2,-\frac{3}{2}\right]$
$\left[-1,-\frac{1}{2}\right]$
$\left[-\frac{3}{2},-1\right]$
Let $S=\{x \in R: \cos (x)+\cos (\sqrt{2} x)<2\}$, then
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