Question

已知函数f（x）=丨x丨+m/x+1

Answer 1

f(2^x)=丨2^x丨+m/2^x+1=2^x+m/2^x+1

设y=2^x 则y>0

y+m/y+1>0

y^2+y+m>0 (y+1/2)^2+m>0 恒成立

1/4+m>0 m>-1/4