Answers in bold:
inputs = [-5, 4]
outputs = [-1, 1]
Is it a function? yes
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Step-by-step explanation:
The domain is the set of allowed x inputs.
The left most point is when x = -5. The right most point happens when x = 4
We can say that "x is between -5 and 4, including both endpoints".
As an inequality, we write the domain to be
and that condenses down to the interval notation [-5, 4]
Use square brackets to include both endpoints.
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The range is the set of allowed y outputs.
The lowest we can go is y = -1, while the highest point occurs when y = 1
Therefore the range is
and that condenses down into the interval notation [-1, 1]
Both endpoints are included.
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Is this relation a function? yes it is
Why? Because each x input in the domain leads to one and only one y output in the range.
The graph passes the vertical line test. This is a test where we try to draw a vertical line passing through more than one point on the curve. But such a task is impossible. Any particular vertical line will pass through the curve at most once.
Because the graph passes the vertical line test, we have a quick visual way to see that we have a function.