Answer:
The explicit equation is:
![\begin{gathered} f(x)=4^x \\ \\ \text{For x = 0,1,2} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/1gdu96cajbvxnn1lysik7s9od51o1dsizl.png)
Step-by-step explanation:
At the beginning, there was only one dot
Day One has 4 dots, and Day Two has 16 dots
Notice that the increase is geometric.
1 to 4 to 16
The common ratio is 4, because 4/1 = 16/4 = 4
So, we have
![y=4^x](https://img.qammunity.org/2023/formulas/mathematics/college/71e8m5xr6j8e4mlzp54a0mlakm06tzuw46.png)
Where y represents the number of dots, and x is the day number.
Let y = f(x), and we have the explicit equation we require
![f(x)=4^x](https://img.qammunity.org/2023/formulas/mathematics/high-school/g23j692pyktb1751039a4ly9p3qe28p0vw.png)
To check
For x = 0 (At the beginning)
![f(0)=4^0=1\text{ dot}](https://img.qammunity.org/2023/formulas/mathematics/college/fa4vgkyihjii4omhyz395dbfizsfmfc4b7.png)
For x = 1 (Day One)
![f(1)=4^1=4\text{ dots}](https://img.qammunity.org/2023/formulas/mathematics/college/iscpwz2z6y11ay4chkrbwqqsljm8n3huzx.png)
For x = 2 (Day Two)
![f(2)=4^2=16\text{ dots}](https://img.qammunity.org/2023/formulas/mathematics/college/4rxvarwovj935im1b6acb522bxrj6cxo9w.png)