Questions tagged [continued-fractions]

A is an expression obtained through an iterative process of representing a number as the sum of its integer part and the reciprocal of another number.

In mathematics, a continued fraction is an expression obtained through an iterative process of representing a number as the sum of its integer part and the reciprocal of another number, then writing this other number as the sum of its integer part and another reciprocal, and so on.

In a finite continued fraction (or terminated continued fraction), the iteration/recursion is terminated after finitely many steps by using an integer in lieu of another continued fraction. In contrast, an infinite continued fraction is an infinite expression. In either case, all integers in the sequence, other than the first, must be positive. The integers ai are called the coefficients or terms of the continued fraction.

Links:

Continued Fraction at Wolfram MathWorld

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How to express an irrational number as generalized continued fraction?

With simple continued fraction, i.e. $$a_0 + \cfrac{1}{a_1 + \cfrac{1}{a_2 + \cfrac{1}{a_3 \ldots}}}$$ I can use this formula: $$a_k = \lfloor \alpha_k \rfloor$$ $$\alpha_{k+1} = \dfrac{1}{\alpha_k - a_k}$$ I wonder is there a formula to express…
roxrook
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How long should you descent in Stern-Brocot-Tree to get a fixed approximation guarantee?

I've read in Wikipedia: By stopping once the desired precision is reached, floating-point numbers can be approximated to arbitrary precision. If a real number x is approximated by any rational number a/b that is not in the sequence of…
Martin Thoma
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Why does this error of a continued fraction decrease by a lot for large entries?

A continued fraction can be seen as a way to approximate numbers with increasingly involved fractions. For example for $\pi$ it is $$\pi=3+\frac{1}{7+\frac{1}{15+\frac{1}{1+\dots}}}$$ Define $\pi_n$ as the number you get by only including $n$ terms…
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Proof of equivalence of two continued fractions

The Problem: Show that $$ \underbrace{a\left(x_1+\cfrac{1}{ax_2+\cfrac{1}{x_3+\cfrac{1}{{ax_4+{}}_{\ddots}}}}\right)}_\text{2n quotients}=\underbrace{ax_1+\cfrac{1}{x_2+\cfrac{1}{ax_3+\cfrac{1}{{x_4+{}}_{\ddots}}}}}_\text{2n quotients} $$ My…
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Continued Fractional representation of irrational numbers

I know that any rational number can be expressed as a continued fraction, but what about irrational numbers? For example, what is the continued fractional representation of Pi, or e for that matter? Can all real numbers be expressed as continued…
Gerard
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How can I find the exact value of this continued fraction?

How can I find the value of $$1 + \cfrac{1}{1 + \cfrac{1}{2 + \cfrac{1}{4 + \cfrac{1}{8 + \cfrac{1}{16 + \cfrac{1}{32 + \cfrac{1}{64 + \ldots}}}}}}}?$$ I have tried approximating the continued fraction and the result is close to $1.6915$. How can I…
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Present as a continued fraction

I want represent the fraction $$\frac{a+b+a b c+a b d}{1+a c+b c+a d+b d+a b c d}\qquad\qquad\qquad (1)$$ as a continued fraction. Here $a,b,c,d$ free variables. I could only get $$\frac{a+b+a b c}{1+b c+a d+b d+a b c…
Vertum
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Proposition about continued fractions

I'm trying to prove the following result: Let $n$ be a fixed natural number and $a_1, a_2, \cdots, a_n$ and $b_1, b_2, \cdots, b_n$ fiexed real values. Then given $\varepsilon>0$, there exits a $\delta>0$ such that if $\left| r-s \right| < \delta$…
Eparoh
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Nth number of continued fraction

Given a real number $r$ and a non-negative integer $n$, is there a way to accurately find the $n^{th}$ (with the integer being the $0^{th}$ number in the continued fraction. If this can not be done for all $r$ what are some specific ones, like $\pi$…
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Continued fraction converging to 1.54

Consider the fraction $1+\frac{2}{3+\frac{4}{5+\frac{6}{7+\frac{8}{9+\frac{10}{11+\frac{12}{13+...}}}}}}$. This fraction approaches about $1.54$ as you continue it. My question is simple. Does anyone have any idea why this converges to this specific…
user558017
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Is every pair of rational numbers a pair of consecutive convergents of some continued fraction?

I've been trying to use Gosper's continued fraction algorithms to work backwards from some randomly chosen pairs of rational numbers but it seems impossible to get arbitrary pairs to be consecutive convergents of a single continued fraction,…
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Bounding error for a generalized continued fraction partial sum

For a regular continued fraction that converges to $\alpha $ we have $\vert \alpha - \frac {A_n}{B_n} \vert < \frac {A_n}{B_n^2}$. Is there a similar result for generalized continued fractions? I need to estimate the accuracy of my $ \frac…
galra
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is there an algorithm that generates the continued fraction of a product of convergent continued fractions?

I understand that there are algorithms (eg a famous one by Gosper) that generate, from certain pairs of continued fractions a, b, the continued fraction of the product. I'm guessing that this algorithm only works for arguments with finite…
sitiposit
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Using continued fraction convergents to find a formula in terms of derivatives

Continued fractions can be represented by the numerator of the nth convergent divided by the denominator of the nth convergent. (See "some useful theorems" on continued fractions). I tried this with the exponential…
tyobrien
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A lower bound for continued fraction approximation.

It is known that, for a continued fraction expansion of an irrational $\alpha$ we have that: $$ \left| \alpha - \frac{p_n}{q_n} \right| = (\alpha_{n+1}q_n^2 + q_nq_{n-1})^{-1} $$ Show that the following lower bound for the error holds: $$ \left|…