Properties of Value of Finite Continued Fraction

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Theorem

Value is Strictly Positive

Let $\sequence {a_0, \ldots, a_n}$ be a finite continued fraction in $\R$ of length $n \ge 0$.

Let all partial denominators $a_k > 0$ be strictly positive.

Let $x = \sqbrk {a_0, a_1, \ldots, a_n}$ be its value.


Then $x > 0$.


Value is at Least First Term

Let $\sequence {a_0, \ldots, a_n}$ be a finite continued fraction in $\R$ of length $n \ge 0$.

Let the partial denominators $a_k > 0$ be strictly positive for $k>0$.

Let $x = [a_0, a_1, \ldots, a_n]$ be its value.


Then $x \ge a_0$, and $x > a_0$ if the length $n \ge 1$.


Floor of Simple Finite Continued Fraction

Let $\sequence {a_k}_{k \mathop \ge 0}$ be a simple finite continued fraction of length $n \ge 0$.

Let $x = [a_0, \ldots, a_n]$ be its value.


Then the floor of $x$ is the partial denominator $a_0$:

$\floor x = a_0$

unless $n = 1$ and $a_1 = 1$, in which case $x = \floor x = a_0 + 1$.


Also see