[微積] tangent line

看板Math作者 (ytyt)時間12年前 (2013/11/13 18:40), 編輯推噓0(003)
留言3則, 2人參與, 最新討論串1/1
Draw a diagram to show that there are two tangent lines to the parabola y=x平方 that pass through the point (0,-4).Find the coordinates of the points where these tangent lines intersect the parabola. 我只找到斜率設一個直線方程式就不知道幹嘛了~哭哭 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 118.168.103.10

11/13 18:47, , 1F
(0,-4)不在曲線上 => 假設切點(t,t^2), 計算兩點斜率
11/13 18:47, 1F

11/13 18:48, , 2F
就能解t了
11/13 18:48, 2F

11/14 16:17, , 3F
Iget it. thx^^
11/14 16:17, 3F
文章代碼(AID): #1IWrSs3V (Math)