What is the domain and range of #f(x) = x^2 + 4x – 6#?
is valid for all Real values of
and therefore the Domain is all Real values i.e.
To determine the Range, we need to find what values of
Probably the simplest way to do this is to generate the inverse relation. For this I will use
Reversing the sides and completing the square:
Re-writing as a square and adding
Taking the square root of both sides
Assuming that we are restricted to Real values (i.e. non-Complex), this expression is valid provided: