MathDB
IMC 2010 - Problem 3

Source:

July 26, 2010
limitfunctionreal analysisreal analysis unsolved

Problem Statement

Define the sequence x1,x2,...x_1, x_2, ... inductively by x1=5x_1 = \sqrt{5} and xn+1=xn22x_{n+1} = x_n^2 - 2 for each n1n \geq 1. Compute limnx1x2x3...xnxn+1\lim_{n \to \infty} \frac{x_1 \cdot x_2 \cdot x_3 \cdot ... \cdot x_n}{x_{n+1}}.