Answer
True.
Work Step by Step
True.
If $x<0$, then $f(x)=x<0$, so $f(x) \neq 4$.
If $x>4$, then $f(x)=-x<0$, so $f(x) \neq 4$.
If $0 \leq x \leq 4$, then $f(x)=x^2=4$ only for $x=2$.
The only solution for the equation $f(x)=4$ is $x=2$.
