Explanation:
the domain is the interval or set of all valid x-values for the function.
and the range is the interval or set of all valid y-values (functional result values) for the function.
so, we can see here that the function would create results for all x in (- infinity, + infinity). that is the domain.
now, what result values (y-values) are possible ?
we see, that the smallest functional value is y = -2.
and from there all y-values up to +infinity are possible.
so, the range is [-2, +infinity).
please consider the chosen brackets. the "[" means the value is included in the function, a "(" means that that particular interval end value is excluded. anything bigger or smaller might be valid but not this one value.
and infinity is not a value. hence they are not included in such intervals.