1.
y=2x^2+2x-1 (x∈R)
2.
y=x/(x+1)
x+1≠0
x≠-1
3.
y=√(x+5)/(x-3)
x+5≥0
x≥-5
x-3≠0
x≠3
x≥-5且x≠3
4.
y=2x/√(x+2)
x+2>0
x>-2
5.
y=√(x^2+1) (x∈R)
6.
y=√(x-2)+√(5-x)
x-2≥0
x≥2
5-x≥0
x≤5
综上:2≤x≤5
1.
y=2x^2+2x-1 (x∈R)
2.
y=x/(x+1)
x+1≠0
x≠-1
3.
y=√(x+5)/(x-3)
x+5≥0
x≥-5
x-3≠0
x≠3
x≥-5且x≠3
4.
y=2x/√(x+2)
x+2>0
x>-2
5.
y=√(x^2+1) (x∈R)
6.
y=√(x-2)+√(5-x)
x-2≥0
x≥2
5-x≥0
x≤5
综上:2≤x≤5