4 Answers:
- Choice A
- Choice D
- Choice E
- Choice F
So basically everything but choices B and C are functions.
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Explanation:
- A. This is a function as there are no repeated input x values. Each input (x) leads to exactly one output (y).
- B. This is not a function. We have the input 2 lead to more than one output (1 and 4 at the same time)
- C. This is not a function. Similar to choice B, we have multiple outputs for a given input. In this case, x = 20 has more than one output.
- D. This is a function. Any x input will produce only one y output. When graphed, it passes the vertical line test.
- E. This is a function. This graph passes the vertical line test. It is not possible to draw a vertical line through more than one point on the blue curve, so that's what I mean by "passing the vertical line test".
- F. This is a function. At any given hour (x), there is exactly one temperature (y) possible. The thermometer is not going to produce multiple readings at any one specific moment in time.
