Question

记函数f(x)=根号下2-[(x+3)/(x+1)]的定义域为A,g(x)=lg[(x-a-1)(2a-x)](a

Answer 1

1 2-[(x+3)/(x+1)]≥0

x-1/x+1≥0

-1＜x≤1

2 (x-a-1)(2a-x)＞0

[x-(a+1)](x-2a)＜0

2a＜x＜a+1

∵B∈A

∴2a≥-1且a+1≤1

a≥-0.5且a≤0

∴-0.5≤a≤0