High School

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

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

Answer :

To solve the problem, we need to evaluate the function [tex]\( f(x) = \left(\frac{1}{9}\right)\left(9^x\right) \)[/tex] for [tex]\( x = 3 \)[/tex].

Step-by-step solution:

1. Substitute [tex]\( x = 3 \)[/tex] into the function:

[tex]\[
f(3) = \left(\frac{1}{9}\right)\left(9^3\right)
\][/tex]

2. Calculate [tex]\( 9^3 \)[/tex]:

[tex]\[
9^3 = 9 \times 9 \times 9 = 81 \times 9 = 729
\][/tex]

3. Multiply by [tex]\(\frac{1}{9}\)[/tex]:

[tex]\[
f(3) = \left(\frac{1}{9}\right) \times 729 = \frac{729}{9}
\][/tex]

4. Perform the division:

[tex]\[
\frac{729}{9} = 81
\][/tex]

Therefore, the value of [tex]\( f(3) \)[/tex] is 81. So, the correct answer is C. 81.