1:点(a,b)在直线2X+3Y+1=O上,则4a+6b+3=?2:点A(-4,2m),B(5,1),C(m,2)在同一条直线上.那么m=?3:过点P(-2,-1)作直线L,使它与点A(3,-5)和B(1,1)的距离相等,则直线L的方程为?
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/20 17:41:55
![1:点(a,b)在直线2X+3Y+1=O上,则4a+6b+3=?2:点A(-4,2m),B(5,1),C(m,2)在同一条直线上.那么m=?3:过点P(-2,-1)作直线L,使它与点A(3,-5)和B(1,1)的距离相等,则直线L的方程为?](/uploads/image/z/10763891-35-1.jpg?t=1%3A%E7%82%B9%28a%2Cb%29%E5%9C%A8%E7%9B%B4%E7%BA%BF2X%EF%BC%8B3Y%EF%BC%8B1%EF%BC%9DO%E4%B8%8A%2C%E5%88%994a%2B6b%2B3%3D%3F2%3A%E7%82%B9A%EF%BC%88%EF%BC%8D4%2C2m%EF%BC%89%2CB%285%2C1%29%2CC%EF%BC%88m%2C2%EF%BC%89%E5%9C%A8%E5%90%8C%E4%B8%80%E6%9D%A1%E7%9B%B4%E7%BA%BF%E4%B8%8A%EF%BC%8E%E9%82%A3%E4%B9%88m%3D%3F3%3A%E8%BF%87%E7%82%B9P%EF%BC%88%EF%BC%8D2%2C%EF%BC%8D1%EF%BC%89%E4%BD%9C%E7%9B%B4%E7%BA%BFL%2C%E4%BD%BF%E5%AE%83%E4%B8%8E%E7%82%B9A%EF%BC%883%2C%EF%BC%8D5%EF%BC%89%E5%92%8CB%EF%BC%881%2C1%EF%BC%89%E7%9A%84%E8%B7%9D%E7%A6%BB%E7%9B%B8%E7%AD%89%2C%E5%88%99%E7%9B%B4%E7%BA%BFL%E7%9A%84%E6%96%B9%E7%A8%8B%E4%B8%BA%3F)
1:点(a,b)在直线2X+3Y+1=O上,则4a+6b+3=?2:点A(-4,2m),B(5,1),C(m,2)在同一条直线上.那么m=?3:过点P(-2,-1)作直线L,使它与点A(3,-5)和B(1,1)的距离相等,则直线L的方程为?
1:点(a,b)在直线2X+3Y+1=O上,则4a+6b+3=?
2:点A(-4,2m),B(5,1),C(m,2)在同一条直线上.那么m=?
3:过点P(-2,-1)作直线L,使它与点A(3,-5)和B(1,1)的距离相等,则直线L的方程为?
1:点(a,b)在直线2X+3Y+1=O上,则4a+6b+3=?2:点A(-4,2m),B(5,1),C(m,2)在同一条直线上.那么m=?3:过点P(-2,-1)作直线L,使它与点A(3,-5)和B(1,1)的距离相等,则直线L的方程为?
点(a,b)在直线2X+3Y+1=O上,所以2a+3b+1=0
4a+6b+3=2(2a+3b+1)+1=1
他们共线,所以斜率相等
1-2m/5+4=2-1/m-5 m=7/2,m=2
设定l方程为 y=kx+2k-1 kx-y+2k-1=0
那么点a到l的距离为|3k+5+2k-1|/根号下(k平房+1)
点b到l的距离为|k-1+2k-1|/根号下(k平房+1)
所以|3k+5+2k-1|=|k-1+2k-1|
|5k+4|=|3k-2|
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