2x²-2x+3a-4=0有两个不相等的实数根
判别式=2^2-4*2*(3a-4)=-24(a-3/2) > 0
a < 3/2
a-2 < 0,a-4<0
|a-2| - 根号(a^2+16-8a )
= |a-2| - 根号(a-4)^2
= |a-2| - |a-4|
=2-a-(4-a)
=-2
2x²-2x+3a-4=0有两个不相等的实数根
判别式=2^2-4*2*(3a-4)=-24(a-3/2) > 0
a < 3/2
a-2 < 0,a-4<0
|a-2| - 根号(a^2+16-8a )
= |a-2| - 根号(a-4)^2
= |a-2| - |a-4|
=2-a-(4-a)
=-2