Find the equation(s) of circle that touches lines x + y = 1 and 2x - y = 4 and passes through point (1, 2).
Equation of circle
2009-08-04 12:28 am
回答 (2)
2009-08-04 6:35 am
2009-08-04 2:31 am
(x+y-1)+k(2x-y-4)=0-(1)
Sub (1,2)into(1),
[(1)+(2)-1]+k[2(1)-(2)-4]=0
2-4k=0
k=1/2
Sub k=1/2 into(1),
(x+y-1)+1/2(2x-y-4)=0
2x+2y-2+2x-y-4=0
4x+y-6=0
So the equation of circle that touches lines x + y = 1 and 2x - y = 4 and passes through point (1, 2)is 4x+y-6=0
Sub (1,2)into(1),
[(1)+(2)-1]+k[2(1)-(2)-4]=0
2-4k=0
k=1/2
Sub k=1/2 into(1),
(x+y-1)+1/2(2x-y-4)=0
2x+2y-2+2x-y-4=0
4x+y-6=0
So the equation of circle that touches lines x + y = 1 and 2x - y = 4 and passes through point (1, 2)is 4x+y-6=0
參考: Myself
收錄日期: 2021-04-22 00:49:25
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090803000051KK01436