14. The domain of the function $y=\sqrt{9-x^{2}} \cdot \lg (1-\sqrt{2} \cos x)$ is $\qquad$ .
$\begin{array}{l}\text { 14. }[-3, \\ \left.\left.-\frac{\pi}{4}\right) \cup\left(\frac{\pi}{4}, 3\right)\right]\end{array}$

The translation is:

$\begin{array}{l}\text { 14. }[-3, \\ \left.\left.-\frac{\pi}{4}\right) \cup\left(\frac{\pi}{4}, 3\right)\right]\end{array}$

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