Note that the function is NOT defined at x = 0
When x is a large negative, f(x) = is only slightly negative, but not 0
When x is a very small negative, f(x) is an extremely LARGE negative verging towards - inf
When x is a small positive, f(x) is a LARGE positive verging towards + inf
When x is a large positive, f(x) is only slightly positive, but not 0
So....the range is (-inf , 0) U (0 , + inf)
The graph here confirms this : https://www.desmos.com/calculator/fmxqof7zjz