求解:\(\sqrt{2-\sqrt{2-\sqrt{2-\sqrt{…}}}}\)

\[ \begin{align*} & 解:\sqrt{2-\sqrt{2-\sqrt{2-\sqrt{…}}}} \\ & 设: t = \sqrt{2-\sqrt{…}} ( t \geq 0 ) \\ & 则: t = \sqrt{2-t} \\ & t^2 = 2-t \\ & t^2+t-2 = 0 \\ & 因式分解(十字交叉) \\ & (t+2)(t-1) = 0 \\ & 解得:t=1,t=-2 (t \geq 0,舍去) \\ 即: & \sqrt{2-\sqrt{2-\sqrt{2-\sqrt{…}}}} = 1 \end{align*} \]

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