thats_right
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共回答了25个问题采纳率:88% 举报
(1)用三点(0,0),(3,0),(-1,4)代入抛物线解析式,求出a,b,c
a=1,b=-3,c=0 解析式为y=x^2-3x
(2)设H(x,0),则S△POH = x*(-x+3)/2,S△HOQ = x*[-(x^2-3x)]
若S△POH :S△HOQ = 1:2,则x = 2
若S△POH :S△HOQ = 2:1,则x = 1/2
(3) 过B做AB的垂线交抛物线与C(有2个),△ABC构成Rt△;同样过A做AB的垂线交抛物线与C
,△ABC构成Rt△;△OAB显然也是.一共有4个
1年前
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