Can someone tell me which is the appropriate domain for this situation?

A function, f(x), represents the height of a plant x months after being planted. Students measure and record the height on a monthly basis.

Select the appropriate domain for this situation.

the set of all positive real numbers

the set of all integers

the set of all positive integers

the set of all real numbers

1 Answer
Jun 26, 2018

Set of positive reals

Explanation:

A plant must always have a height, therefore it's height can never be negative. This rules out the set of all Integers and all reals.

Now, as the height can exist between numbers such as 5.5 cm at some point in time this means the height can not be only a positive integer.

This leaves only the set of positive reals as a possible domain.