Question

How do you find the domain and range of `f(x) = x^2 + 1`?

Answer 1

Domain: `RR`
Range: `RR >=1`

Explanation:

`f(x)=x^2+1` is defined for all Real values of `x`;
therefore the Domain of `f(x)` is all Real values (i.e. `RR`).

`x^2>=0` for all Real values of `x`
`rarr x^2+1 >=1` for all Real values of `x`
therefore the Range of `f(x)` is all Real values `>= 1`