The graph of $y=f(x)$ for $-3\le x\le 3$ is shown below. On this interval, what is the range of $f(x)-x$? Express your answer in interval notation.
Note that in each "piecewise" part of the function, the greatest value of [f(x) - x] occurs at the left part of the interval and is 0
And note that the least value of f(x) - x occurs at the right part of the piecewise interval and is "almost" -1
So...the range of f(x) - x is ( -1, 0 ]