1.X∈R,y=(x-1)^2+1>=1,即y>=1,y∈[1,+∞]
2.x∈[-5,0],y=(x-1)^2+1在x=-5时最大,y=37,在x=0时最小,y=2,y∈[2,37]
3.x∈[-5,5],y=(x-1)^2+1在x=-5时最大,y=37,在x=1时最小,y=1,y∈[1,37]
4.x∈（0,+∞）,y=(x-1)^2+1在在x=1时最小,y=1,y∈[1,+∞]