x^2 + x + 1
________
x^2 + 1
We would need Calculus to determine this mathematically......a graph might work better
Look here : https://www.desmos.com/calculator/ndujaokd6r
The max value for y occurs at (1, 1.5)
And the minimum value for y occurs at (-1, 0.5)
And all y values between these are defined
So.....the range is [ 0.5, 1.5 ]