Re: [中學] 向量1題
: 答案是外心 想問推導過程 感謝
OA^2 + BC^2 = OB^2 + AC^2 = OC^2 + AB^2
=> OC * OB = OC * OA = OB * OA
=> OC * AB = OB * AC = OA * BC = 0
=> O是垂心 = H
OP = (1/2)[OA + OB + OC]
=> HP = (3/2)HG
因為2O'G = GH，O'為外心
=> HP = -3O'G = -O'H
=> P = O'外心
--
※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 118.165.144.191 (臺灣)
※ 文章網址: https://www.ptt.cc/bbs/Math/M.1610739756.A.280.html
討論串 (同標題文章)
