If $f(x)$ is a function whose domain is $[-1,9]$, and $g(x)=f(x^2)$, then the domain of $g(x)$ is an interval of what width?

The domain of g is [-1,3], so the witdh of the interval is 4.

g(x) = (f(x))^2 is defined over the same interval as f(x) [-1,9] interval width is 10