Continued Fraction Comparisons

Problem

Define a sequence {bn}\{b_n\} of continued fractions by

b1=1+1α1,b2=1+1α1+1α2,b3=1+1α1+1α2+1α3,b_1 = 1 + \frac{1}{\alpha_1}, \quad b_2 = 1 + \frac{1}{\alpha_1 + \frac{1}{\alpha_2}}, \quad b_3 = 1 + \frac{1}{\alpha_1 + \frac{1}{\alpha_2 + \frac{1}{\alpha_3}}}, \quad \dots

where each αkN\alpha_k \in \mathbb{N}^*. Determine, with proof, which of the following always hold:

1. b1<b5b_1 < b_5; 2. b3<b8b_3 < b_8; 3. b6<b2b_6 < b_2; 4. b4<b7b_4 < b_7.

Answer

Solution

Difficulty6/10
Topicsnumber theory, Monotonicity, sequences, Continued Fractions

Whiteboard

Your sketch is saved only in this browser. To share it, export your drawing as an image (whiteboard menu → Export as → PNG), then upload that image in the comments below.

Discussion

Ask questions, share alternate solutions, and use LaTeX freely.

0 comments
Log in to join the discussion.

No comments yet.