※ 引述《peecome (bunnyplaycat)》之铭言： : Take a stick of unit length and break it into two pieces, choosing the break : point at random. Now break the longer of the two pieces at a random point. : What is the probability that the three pieces can be used to form a triangle? : 想请问大家觉得该怎麽解? : 我令一推随机变数越来越复杂... : 谢谢.. x1 x1 ├──┼────┼──┼────┤ 0 x1 x2 x3 1 假设长度为1 第一点如果取在x1 则 第二点只能取在x2跟x3之间 常会形成三角形 算x1在左半的机率 再乘2 1/2 2*∫ 1 * x/(1-x) dx = 2log2 - 1 0 有错请告知^^ --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 140.112.50.186