High School

If [tex]$f(x)=\left(\frac{1}{7}\right)\left(7^x\right)$[/tex], what is [tex]$f(3)$[/tex]?

A. 49
B. [tex]$\frac{1}{343}$[/tex]
C. 343
D. [tex]$\frac{1}{49}$[/tex]

Answer :

To solve the problem of finding [tex]\( f(3) \)[/tex] for the function [tex]\( f(x) = \left(\frac{1}{7}\right)\left(7^x\right) \)[/tex], we will follow these steps:

1. Substitute [tex]\( x \)[/tex] in the function with 3:
This means we need to calculate [tex]\( f(3) \)[/tex].

2. Evaluate the expression:
The function is given as [tex]\( f(x) = \left(\frac{1}{7}\right)\left(7^x\right) \)[/tex].
Substitute 3 for [tex]\( x \)[/tex]: [tex]\( f(3) = \left(\frac{1}{7}\right)\left(7^3\right) \)[/tex].

3. Calculate [tex]\( 7^3 \)[/tex]:
[tex]\( 7^3 = 7 \times 7 \times 7 = 343 \)[/tex].

4. Multiply by [tex]\( \frac{1}{7} \)[/tex]:
Since we have [tex]\( f(3) = \frac{1}{7} \times 343 \)[/tex], we will divide 343 by 7.

5. Division:
[tex]\( 343 \div 7 = 49 \)[/tex].

So, after performing these calculations, we find that [tex]\( f(3) = 49 \)[/tex].

Therefore, the answer is A. 49.