如图
(1)Δ>04-4(m-1) >04m<8m<2 (2)x^2-2x+m-1=0x1+x2=2x1.x2 = m-1(x1)^2+(x^2)^2=6x1.x2(x1+x2)^2 = 8x1.x24=8(m-1)8m=12m=3/2
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