α2 +β 2=(α+β)²-2αβ=4m²-2(1-m²)=6m²-2
α,β是方程x2-2mx+1-m2=0 (m∈R)的两个实根
4m²-4(1-m²)≥0
m²≥1/2
α2 +β 2=(α+β)²-2αβ=4m²-2(1-m²)=6m²-2≥6*1/2-2=1
最小值=1
选C.1
α2 +β 2=(α+β)²-2αβ=4m²-2(1-m²)=6m²-2
α,β是方程x2-2mx+1-m2=0 (m∈R)的两个实根
4m²-4(1-m²)≥0
m²≥1/2
α2 +β 2=(α+β)²-2αβ=4m²-2(1-m²)=6m²-2≥6*1/2-2=1
最小值=1
选C.1