College

If [tex]f\left(x_i\right)=\left(\frac{1}{g}\right)\left(9^{x^*}\right)[/tex], what is [tex]f(3)[/tex]?

A. 81
B. 729
C. [tex]\frac{1}{729}[/tex]
D. [tex]\frac{1}{81}[/tex]

Answer :

We are given the function

[tex]$$
f\left(x_i\right)=\frac{1}{g} \cdot 9^{x^*}.
$$[/tex]

Assuming that the star in the exponent indicates that the exponent is the value of our input (i.e., [tex]$x_i = x^*$[/tex]) and that the constant [tex]$g$[/tex] is equal to 1, we can rewrite the function as

[tex]$$
f(x)=\frac{1}{1} \cdot 9^x = 9^x.
$$[/tex]

Now, to find [tex]$f(3)$[/tex] we substitute [tex]$x=3$[/tex]:

[tex]$$
f(3)=9^3.
$$[/tex]

Evaluating [tex]$9^3$[/tex]:

[tex]$$
9^3=9\cdot9\cdot9=81\cdot9=729.
$$[/tex]

Thus, the value of [tex]$f(3)$[/tex] is

[tex]$$
\boxed{729}.
$$[/tex]