1、[-2(m+1)]^2-4m^2>=0
4m^2+8m+4-4m^2>=0
m>=-1/2
令m=0
则x^2-2x=0
x(x-2)=0
x=0,x=2
2、x1+x2=3/2,x1x2=1/2
x1^2+x2^2=(x1+x2)^2-2x1x2=9/4-1=5/4
1/x1+1/x2=(x1+x2)/x1x2=(3/2)/(1/2)=3
x1^2x2+x1x2^2=x1x2(x1+x2)=3/4
3、判别式大于等于0
所以4a^2-12a+9-4a^2+4a>=0
a=-4
6、整理
(c-a)x^2+2bx+(a+c)=0
所以判别式4b^2-4(c-a)(c+a)=0
b^2-(c^2-a^2)=0
b^2-c^2+a^2=0
c^2=a^2+b^2
所以是直角三角形
7、x1+x2=-(-2)/2=1,x1x2=(1-3m)/2
x1*x2+2(x1+x2)>0
(1-3m)/2+2*1>0
1-3m>-4
m=0
m>=1/6
所以 1/6《=m〈5/3
8、把x=0代入,0-0+3k^2-1=0
k=正负根号3/3
x1+x2=0
2(3k+1)/3=0
k=-1/3