(sin15555555555555⋯∘)×10000000000⋯=π(\sin{\frac{1}{5555555555555\cdots}}^{\circ})\times10000000000\cdots=\pi(sin5555555555555⋯1 ∘)×10000000000⋯=π
π=limn→∞(sin15×10n−19)×10n+2\pi=\lim\limits_{n\to\infty}(\sin{\frac{1}{5\times\frac{10^{n}-1}{9}}})\times10^{n+2}π=n→∞lim (sin5×910n−1 1 )×10n+2