Question

方程4x^2-4(m-1)x+m^2=7的两根之差的绝对值大于2的充分条件是?

Answer 1

x1= 1/2 (-1 - Sqrt[8 - 2 m] + m) ,

x2= 1/2 (-1 + Sqrt[8 - 2 m] + m)

Abs[x1-x2]=Sqrt[8-2m]

Sqrt[8-2m] >2

==> m