What is the domain of the quadratic function given by f(x) = 2x2 + 2x - 4?
1 answer:
B. All real numbers :)
The only conern here is that you are able to square x. Since the square of any real number gives a real number answer, then that is the domain.
If the function was
, then the domain woudl be all POSITIVE real numbers since you cannot take the square root of a negative number. Try it on your calculator! you will get an error! Domain simply means all possible values for x that actually give real number answers.
(the opposite of a real number is an imaginary number, like 'i' = [tex]\sqrt{-1}[tex]. You can see that you cannot sqrt a negative number, yet, in quantum mechanics 'i' is used all the time because it makes things work in calculations.
The only conern here is that you are able to square x. Since the square of any real number gives a real number answer, then that is the domain.
If the function was
(the opposite of a real number is an imaginary number, like 'i' = [tex]\sqrt{-1}[tex]. You can see that you cannot sqrt a negative number, yet, in quantum mechanics 'i' is used all the time because it makes things work in calculations.
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