{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Square root convergents (Euler Problem 57)" ] }, { "cell_type": "markdown", "metadata": { "collapsed": true }, "source": [ "[https://projecteuler.net/problem=57](https://projecteuler.net/problem=57)\n", "\n", "It is possible to show that the square root of two can be expressed as an infinite continued fraction.\n", "\n", "√ 2 = 1 + 1/(2 + 1/(2 + 1/(2 + ... ))) = 1.414213...\n", "\n", "By expanding this for the first four iterations, we get:\n", "\n", "1 + 1/2 = 3/2 = 1.5\n", "\n", "1 + 1/(2 + 1/2) = 7/5 = 1.4\n", "\n", "1 + 1/(2 + 1/(2 + 1/2)) = 17/12 = 1.41666...\n", "\n", "1 + 1/(2 + 1/(2 + 1/(2 + 1/2))) = 41/29 = 1.41379...\n", "\n", "The next three expansions are 99/70, 239/169, and 577/408, but the eighth expansion, 1393/985, is the first example where the number of digits in the numerator exceeds the number of digits in the denominator.\n", "\n", "In the first one-thousand expansions, how many fractions contain a numerator with more digits than denominator?" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [] } ], "metadata": { "completion_date": "", "kernelspec": { "display_name": "Python 3", "language": "python3.6", "name": "python3" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 3 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython3", "version": "3.6.5" }, "tags": [] }, "nbformat": 4, "nbformat_minor": 2 }