Find the equation of the two lines through (2,6), each making an angle of 45 degree with the line 5x-y+4=0
Thanks!
A. MATHS. Straight lines problem (急)
2006-12-20 6:39 am
回答 (1)
2006-12-20 6:56 am
✔ 最佳答案
let the slope of the required line is mthe slope of 5x-y+4=0 is 5
so
tan45=|(m-5)/(1+5m)|
(m-5)/(1+5m)=1 or (m-5)/(1+5m)=-1
m-5=1+5m or m-5=-1-5m
m=-3/2 or m=2/3
when m=-3/2
the line is
y-6=(-3/2)(x-2)
2y-12=-3x+6
3x+2y-18=0
when m=2/3
y-6=(2/3)(x-2)
3y-18=2x-4
2x-3y+14=0
收錄日期: 2021-04-25 16:49:11
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