another function problem

Question

If f(x)=x-1, g(x)=x³, and x≤0, which of the following couldn't be in the range of f(g(x))?

Answer 1

Anna,

 

f(x) = x-1

g(x) = x³

therefore

f(g(x)) = x³-1

 

Since x≤0, x³≤0

and x³-1≤-1

 

It appears this may have been a multiple choice problem.  The solution must be less than or equal to -1.