wlllp
幼苗
共回答了16个问题采纳率:100% 举报
A (a,a^2/4),B (0,2)
圆A:(x-a)^2+(y-a^2/4)^2=a^2+(2-a^2/4)^2=4+a^4 /16
M,N:
(x-a)^2+(a^2/4)^2=4+a^4 /16
(x-a)^2=4
x-a=2,-2
M,N:(a+-2,0)
|MN|=4,不变.
MOB BON
OM/OB=OB/ON
OM*ON=OB^2
(a+2)(a-2)=4
a^2=8
a=+-2sqrt2
M (2sqrt2,0) or (-2sqrt2,0)
1年前
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