Answer: Third option.
Step-by-step explanation:
<h3> The exercise is actually: "Identify the variation as direct, inverse, joint or combined:For this exercise it is important to remember that, by definition, a Joint variation is that variation in which one variable depends on two or more variables and there are a direct relation between these variables.
In this case, you have the following equation given in the exercise:
Let's assume that "r" and "h" are variables.
You can identify that:
- The variable "V" depends on the variables "r" and "h".
- The variables are related directly.
So, based on this, the variation can be read as:
<em>"V" varies jointly with the square of "r" and "h".</em>
Therefore, you can conclude that the given variation is: Joint.