Quantcast
Channel: Quod Erat Demonstrandum
Viewing all articles
Browse latest Browse all 265

pi的連分表達式

$
0
0

\pi 寫成連分數(continued fraction),方式甚多,以下是其中一種:

可以變成 M2 習題如下:

Define \displaystyle I_n=\int_0^1\frac{x^{2n}}{1+x^2}dx.

(a) Show that I_n+I_{n+1}=\frac{1}{2n+1}.

(b) Express \displaystyle \frac{I_n+I_{n+1}}{I_{n+1}+I_{n+2}} in terms of n.

Define \displaystyle a_n=\frac{I_{n+1}}{I_n}.

(c) Show that a_0=\frac{4}{\pi}-1.

(d) Prove that \displaystyle a_n=\frac{2n+1}{2+(2n+3)a_{n+1}}.

(e) Hence, show that

做 (e) 提示:由 a_0 出發,瘋狂地運用 (d),即

a_0

=\displaystyle \frac{1}{2+3a_1}

=\displaystyle \frac{1}{2+3\times \frac{3}{2+5a_2}}

=\displaystyle \frac{1}{2+\frac{3^2}{2+5\times \frac{5}{2+7a_3}}}

=\displaystyle \frac{1}{2+\frac{3^2}{2+\frac{5^2}{2+\dots}}}

\dots

從略。

上月在推特見下式,想玩玩嗎?

隨便搜尋~
https://www.google.com/search?safe=strict&biw=1920&bih=925&tbm=isch&sa=1&ei=1BxIW5-UKo2JoASzgbioCA&q=pi+continued+fraction&oq=pi+continued+fraction&gs_l=img.3…0.0.0.12244396.0.0.0.0.0.0.0.0..0.0….0…1c..64.img..0.0.0….0.GXa0S_usVOM


Viewing all articles
Browse latest Browse all 265

Trending Articles