tangxiaowo
幼苗
共回答了23个问题采纳率:91.3% 举报
1.∵一元二次方程X^2+(2M-1)X+M^2=0有两个实数根X1 和X2,
∴△≥0
即:b^2 - 4ac=(2M-1)^2 - 4M^2 =-4M+1≥0
∴M≤1/4
2.x1+x2=1-2m ,x1x2=m^2
(x1-x2)^2 =(x1+x2)^2 - 4x1x2 =(1-2m)^2 - 4m^2 =1-4m
x1-x2=±√1-4m
x1^2 - x2^2 =(x1+x2)(x1-x2)=(1-2m)(√1-4m)=0或(1-2m)(-√1-4m)=0
m=1/2 或 m=1/4
∵方程有实根
∴m=1/2舍
m=1/4
1年前
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