close

標題:

 

此文章來自奇摩知識+如有不便請留言告知

Equations of straight lines

發問:

Find the equation of the line L passing through the point (8,1) and the intersection of the lines L1: 2x+2y-3=0 L2: 6x-7y-7=0

最佳解答:

Find the equation of the line L passing through the point (8,1) and the intersection of the lines L1: 2x+2y-3=0 ------------(1) L2: 6x-7y-7=0 -----------(2) (1)*3 - (2), 6x + 6y - 9 - 6x + 7y + 7 = 0 13y = 2 y = 2/13 Sub y = 2/13 into (1) 2x + 2/13 - 3 = 0 2x - 37/13 = 0 2x = 37/13 x = 37/26 Intersection point of L1,L2 = (37/26, 2/13) Slope of the required equation = (1 - 2/13)/(8 - 37/26) = (24/13)/(171/26) = 48/171 Hence, the required equation: (y - 1) = 48(x-8)/171 171y - 171 = 48x - 384 171y = 48x - 213

其他解答:

Let the line be 2x+2y-3+k(6x-7y-7)=0 Sub (8,1) into it, 16+2-3+k(48-7-7)=0 15+34k=0=>k=-15/34 Hence the line is 2x+2y-3-(15/34)(6x-7y-7)=0 68x+68y-102-90x+105y+105=0 173y-22x+3=00D7DAC4E6DF60DFA

arrow
arrow
    文章標籤
    周率頭 丁家 音效 程式 教室
    全站熱搜
    創作者介紹
    創作者 kfsdgte 的頭像
    kfsdgte

    kfsdgte的部落格

    kfsdgte 發表在 痞客邦 留言(0) 人氣()

    E-mail轉寄