Respuesta :
The general basic exponential function is of the form,
[tex]y=na^{kx} ---(1) [/tex]
The function has a [tex]y[/tex] intercept of [tex](0,3)[/tex]
This point must satisfy equation (1). So let us do the substitution to obtain,
[tex]3=na^{k(0)}[/tex]
[tex]\Rightarrow 3=n \times a^{0}[/tex]
[tex]\Rightarrow 3=n \times 1[/tex]
[tex]\Rightarrow n=3[/tex]
Now our equation 1 becomes
[tex]y=3a^{kx} ---(2)[/tex]
Also note that the graph passes through, [tex](1,1)[/tex], hence must also satisfy its equation. Substituting this point into equation (2), gives us
[tex]1=3a^{k(1)}[/tex]
[tex]\Rightarrow \frac{1}{3}=a^{k}[/tex]
Equation (2) can be rewritten as;
[tex]y=3(a^{k})^x ---(3)[/tex]
Now let us substitute the value of [tex]{a}^{k}=\frac{1}{3}[/tex] into equation (3) to obtain,
[tex]y=3(\frac{1}{3})^x [/tex]
Hence the correct answer is option B
The graph illustrates an exponential function.
The function of the graph is: [tex]\mathbf{y = 3(\frac 13)^x}[/tex]
An exponential function is represented as:
[tex]\mathbf{y = ab^x}[/tex]
From the graph, we have the following points
[tex]\mathbf{(x,y) = (1,1)}[/tex]
[tex]\mathbf{(x,y) = (0,3)}[/tex]
Substitute [tex]\mathbf{(x,y) = (0,3)}[/tex] in [tex]\mathbf{y = ab^x}[/tex]
[tex]\mathbf{3 = ab^0}[/tex]
[tex]\mathbf{3 = a\times 1}[/tex]
[tex]\mathbf{3 = a}[/tex]
Rewrite as:
[tex]\mathbf{a = 3}[/tex]
Substitute [tex]\mathbf{(x,y) = (1,1)}[/tex] in [tex]\mathbf{y = ab^x}[/tex]
[tex]\mathbf{1 = ab^1}[/tex]
[tex]\mathbf{1 = ab}[/tex]
Substitute [tex]\mathbf{a = 3}[/tex]
[tex]\mathbf{1 = 3b}[/tex]
Divide both sides by 3
[tex]\mathbf{b = \frac 13}[/tex]
Substitute [tex]\mathbf{a = 3}[/tex] and [tex]\mathbf{b = \frac 13}[/tex] in [tex]\mathbf{y = ab^x}[/tex]
[tex]\mathbf{y = 3(\frac 13)^x}[/tex]
Hence, the exponential function is: [tex]\mathbf{y = 3(\frac 13)^x}[/tex]
Read more about exponential functions at:
https://brainly.com/question/11487261