\(\mathop {\lim }\limits_{x \to 0} \frac{{1 - \sin 2x - \cos 2x}}{{1 - \sin 2x + \cos 2x}}\)
Giải chi tiết:
\(\mathop {\lim }\limits_{x \to 0} \frac{{1 - \sin 2x - \cos 2x}}{{1 - \sin 2x + \cos 2x}} = \mathop {\lim }\limits_{x \to 0} \frac{{2{{\sin }^2}x - 2\sin x\cos x}}{{2{{\cos }^2}x - 2\sin x\cos x}}\)
\( = \mathop {\lim }\limits_{x \to 0} \frac{{2\sin x\left( {\sin x - \cos x} \right)}}{{2\cos x\left( {\cos x - \sin x} \right)}} = \mathop {\lim }\limits_{x \to 0} \frac{{ - \sin x}}{{\cos x}} = 0\).
Chọn C.