Write an exponential function for a graph that includes the points (1, 12) and (0,9).

Answer:
The exponential function is;
[tex]y=9(\frac{4}{3})^x[/tex]Explanation:
Given that the function is an exponetial function.
It is of the form;
[tex]y=ab^x[/tex]And the function contains the points;
[tex]\begin{gathered} (1,12) \\ \text{and} \\ (0,9) \end{gathered}[/tex]so, substituting the values of x and y for each point;
[tex]\begin{gathered} 12=ab^1 \\ 12=ab\text{ -------1} \\ 9=ab^0 \\ 9=a\text{ ----------2} \end{gathered}[/tex]dividing equation 1 by 2;
[tex]\begin{gathered} \frac{12}{9}=\frac{ab}{a} \\ b=\frac{12}{9} \\ b=\frac{4}{3} \\ \text{and } \\ a=9 \end{gathered}[/tex]Therefore, substituting a and b, the equation gives;
[tex]\begin{gathered} y=ab^x \\ y=9(\frac{4}{3})^x \end{gathered}[/tex]Therefore, the exponential function is;
[tex]y=9(\frac{4}{3})^x[/tex]