(2)原方程整理得
x²-(2m-6)x+(m²-4m+3)=0
若两根为x1和x2,
则x1+x2=2m-6,x1*x2=m²-4m+3,
x1x2-x1 ²-x2 ²
=-(x1+x2)²+3x1x2
=-(2m-6)²+3(m²-4m+3)
=-m²+12m-27
=-(m-6)²+9
∴m=6 时有最大值为 9
(2)原方程整理得
x²-(2m-6)x+(m²-4m+3)=0
若两根为x1和x2,
则x1+x2=2m-6,x1*x2=m²-4m+3,
x1x2-x1 ²-x2 ²
=-(x1+x2)²+3x1x2
=-(2m-6)²+3(m²-4m+3)
=-m²+12m-27
=-(m-6)²+9
∴m=6 时有最大值为 9