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If f(x) = 2x² − x, what is f(3)?

What is the domain of f(x) = √(x + 5)?

[5, ∞[

[−5, ∞[

]−5, ∞[

]−∞, −5]

What is the domain of f(x) = 4 / (x − 7)?

All real numbers except −7

All real numbers except 4

All real numbers except 7

All real numbers except 0

Is the relation x² + y = 4 a function of x?

No, because the relation contains x²

No, because each value of x gives two values of y

Yes, because each value of y gives exactly one value of x

Yes, because each value of x gives exactly one value of y

Is the relation x² + y² = 4 a function of x?

No, because x = 0 gives y = 2 or y = −2

Yes, because each value of x gives exactly one value of y

No, because x = 2 gives no value of y

Yes, because y² appears in the relation

If f(x) = 1 / (x + 2), what value of x makes f(x) = 1/2?

−2

Real Functions — Lesson quiz