Question

求函数f(x)=x*2+1 / x*2+2x-1 的值域

Answer 1

1、设y=X^2/(X^2+1),(y≥0,y≠1)

则(1-y)X^2=y,X^2=y/(1-y)

Y/(1-Y)≥0得0≤y≤1,∴0≤y