韦达定理,得:α+β=m,αβ=(22+m)/4
∴(α-1)²+(β-1)²=α²+β²-2α-2β+2
=(α+β)²-2αβ-2(α+β)+2
=m²-(22+m)/2-2m+2
=m²-5/2*m-9
=(m-5/4)²-25/16-9
=(m-5/4)²-169/16
而Δ=16m²-4×4(22+m)≥0,即m²-m-22≥0
【额,我想说,你题目是不是抄错了,方程是4x²-4mx+2+m=0啊】
韦达定理,得:α+β=m,αβ=(22+m)/4
∴(α-1)²+(β-1)²=α²+β²-2α-2β+2
=(α+β)²-2αβ-2(α+β)+2
=m²-(22+m)/2-2m+2
=m²-5/2*m-9
=(m-5/4)²-25/16-9
=(m-5/4)²-169/16
而Δ=16m²-4×4(22+m)≥0,即m²-m-22≥0
【额,我想说,你题目是不是抄错了,方程是4x²-4mx+2+m=0啊】