Using it's concept, the rate of change between point C and point D is of 2.
<h3>What is the average rate of change of a function?</h3>
The average rate of change of a function is given by the <u>change in the output divided by the change in the input</u>. Hence, over an interval [a,b], the rate is given as follows:
![r = \frac{f(b) - f(a)}{b - a}](https://tex.z-dn.net/?f=r%20%3D%20%5Cfrac%7Bf%28b%29%20-%20f%28a%29%7D%7Bb%20-%20a%7D)
Considering the points of the given linear function, we have that:
Hence the rate of change between point C and point D is given by:
r = (4 - 2)/(2 - 1) = 2.
More can be learned about the average rate of change of a function at brainly.com/question/24313700
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