At what points does a limit exists

these are the "equations" of the line.

https://webwork2.math.uga.edu/webwork2_f…

i thought the answer would be (-infty,-1] U [-1,1] u [1,+infty) (all numbers but -1, 1) but apparently that's not it. help?

Close, but there's also a jump - technically a "discontinuity" - on each side of zero, from x (approaching zero) to 1 (at zero) back to x (near zero on the other side.). Also, the intervals don't include the endpoints, so you need to use parentheses rather than brackets.

(-inf, -1) U (-1, 0) U (0, 1) U (1, +inf)