Question

The temperature in degrees Celsius, c, can be converted to degrees Fahrenheit, f, using the equation f = StartFraction 9 Over 5 EndFraction c + 32. Which statement best describes if the relation (c, f) is a function?
It is a function because –40°C is paired with –40°F.
It is a function because every Celsius temperature is associated with only one Fahrenheit temperature.
It is not a function because 0°C is not paired with 0°F.
It is not a function because some Celsius temperatures cannot be associated with a Fahrenheit temperature.

Answer 1

It is a function because every Celsius temperature is associated with only one Fahrenheit temperature.

Explanation: f = (9/5)c + 32 is a linear rule that assigns exactly one f-value to each c-value (for every real c there is a single corresponding f), so the relation is a function.