Answer: Choice B
Range = {0, -18}
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Step-by-step explanation:
The domain is the set of allowed x inputs.
In this case, we're only allowed to plug in x = -3, x = 0 or x = 3.
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Plug x = -3 into the function to get
f(x) = -2x^2
f(-3) = -2(-3)^2
f(-3) = -2*9
f(-3) = -18
The input x = -3 leads to the output y = -18
So -18 is one value in the range.
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Repeat for x = 0
f(x) = -2x^2
f(0) = -2(0)^2
f(0) = -2*0
f(0) = 0
That means y = 0 is also in the range
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Repeat for x = 3
f(x) = -2x^2
f(3) = -2(3)^2
f(3) = -2*9
f(3) = -18
We get -18 again like we did earlier. This is because (-3)^2 and (3)^2 have the same result.
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The outputs we got were: -18, 0, -18
Effectively, the range is {-18, 0} which is the same as {0, -18} so that's why choice B is the answer.
Note: We don't list any repeat values when it comes to the domain or range.