回復 2# Exponential 的帖子
\(\begin{align}
& {{a}_{1}}=2\ ,\ {{a}_{n+1}}=\frac{1}{1-{{a}_{n}}} \\
& {{a}_{2}}=-1\ ,\ {{a}_{3}}=\frac{1}{2}\ ,\ {{a}_{4}}=2 \\
& \\
& a\sin \left( \frac{2\pi }{3}+\theta \right)+b=2 \\
& a\sin \left( \frac{4\pi }{3}+\theta \right)+b=-1 \\
& a\sin \left( 2\pi +\theta \right)+b=\frac{1}{2} \\
& a=\sqrt{3}\ ,\ \theta =0\ ,\ b=\frac{1}{2} \\
& \\
& {{a}_{n}}=\sqrt{3}\sin \left( \frac{2n\pi }{3} \right)+\frac{1}{2} \\
\end{align}\)
