L1 3X+4Y-9=0
L2 0=(K+2)X+(K-5)
若L1//L2 ,求K
答案K=-11/4
L1 2X+5Y-11=0
L2 KX+4Y+5=0
L1┴L2 求K
答案K=-10
中4數一問,求步驟,有答案
2011-02-28 7:43 pm
回答 (1)
2011-02-28 8:03 pm
✔ 最佳答案
L1 :3X+4Y-9=0Y = (- 3/4)X + 9/4
L2 是 Y = (K+2)X + (K-5)由 y = mx + c , (m 是斜率) :L1 斜率 = - 3/4
L2 斜率 = (K+2)L1 // L2 , 所以(K+2) = - 3/4K = - 11/4
;
L1
2X+5Y-11=0
Y = (-2/5)X + 11/5
L2
KX+4Y+5=0
Y = (- K/4)X - 5/KL1 斜率 = - 2/5
L2 斜率 = - K/4L1┴L2 , 故(- 2/5) * (- K/4) = - 12K/20 = - 1K = - 10
收錄日期: 2021-04-21 22:22:29
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https://hk.answers.yahoo.com/question/index?qid=20110228000051KK00402