正月里来是新春
幼苗
共回答了11个问题采纳率:100% 举报
x+2y-3=0
x=3-2y,代入圆E方程,整理得:5y^2-16y+6+m=0
y1+y2=16/5 y1y2=(6+m)/5
x1x2=(3-2y1)(3-2y2)
=9-6*16/5+4(6+m)/5
=(4m-27)/5
(1)OP*OQ=0 x1x2+y1y2=0
(4m-27)/5+(6+m)/5=0
m=21/5
(2)EP*EQ=0
E:(x-1/2)^2+(y-3)^2=37/4-m E(1/2,3)
EP=(x1-1/2,y1-3) EQ=(x2-1/2,y2-3)
(x1-1/2)(x2-1/2)+(y1-3)(y2-3)=0
x1x2-(x1+x2)/2+1/4+y1y1-3(y1+y2)+9=0
m=87/20
1年前
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