判别式=(2m-3)^2-4(m^2+1)=5-12m大于等于0,得m小于等于5/12.
因为两根积x1*x2=m^2+1为正数,故两根同号,同正时,x1+x2=2m-3=3,m=3(舍去)
同负时,-x1-x2=-2m+3=3,m=0
1)△=(2m-3)^2 -4(m^2+1)
=-12m+5 ≥0
m≤5/12
2)因为方程有两根即 △>0 m<5/12
设方程的两根为x1 x2
x1+x2=2m-3 <-13/6
x1x2=m^2+1
即x1+x2<0
x1x2>0
所以x1,x2都是负根
|x1|+|x2|= -(x1+x2)= -(2m-3)=3
m=0