Question

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

Answer 1

2-(x+3)/(x+1)>=0

(2x+2-x-3)/(x+1)>=0

(x-1)(x+1)>=0

x+1在分母,不等于0

所以A={x|x>=1,x