College

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

Answer :

Let's solve the problem step-by-step to find the value of [tex]\( f(3) \)[/tex].

Given the function:
[tex]\[ f(x) = \left( \frac{1}{9} \right) \left( 9^x \right) \][/tex]

We need to find [tex]\( f(3) \)[/tex].

Step 1: Substitute [tex]\( x = 3 \)[/tex] into the function:
[tex]\[ f(3) = \left( \frac{1}{9} \right) \left( 9^3 \right) \][/tex]

Step 2: Calculate [tex]\( 9^3 \)[/tex]:
[tex]\[ 9^3 = 9 \times 9 \times 9 = 81 \times 9 = 729 \][/tex]

Step 3: Now, multiply by [tex]\( \frac{1}{9} \)[/tex]:
[tex]\[ f(3) = \left( \frac{1}{9} \right) \left( 729 \right) \][/tex]

Step 4: Simplify the multiplication:
[tex]\[ \frac{1}{9} \times 729 = \frac{729}{9} = 81 \][/tex]

So, [tex]\( f(3) = 81 \)[/tex].

Therefore, the correct answer is:
[tex]\[ \boxed{81} \][/tex]