High School

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

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

Answer :

Let's solve the problem step by step:

We are given the function [tex]\( f(x) = \left(\frac{1}{7}\right)\left(7^x\right) \)[/tex] and asked to find [tex]\( f(3) \)[/tex].

1. Substitute 3 into the function:
Start by replacing [tex]\( x \)[/tex] with 3 in the function.

[tex]\[
f(3) = \left(\frac{1}{7}\right)\left(7^3\right)
\][/tex]

2. Calculate [tex]\( 7^3 \)[/tex]:
Calculate [tex]\( 7^3 \)[/tex], which means 7 multiplied by itself three times.

[tex]\[
7^3 = 7 \times 7 \times 7 = 343
\][/tex]

3. Multiply by [tex]\(\frac{1}{7}\)[/tex]:
Now, multiply the result by [tex]\(\frac{1}{7}\)[/tex].

[tex]\[
f(3) = \left(\frac{1}{7}\right) \times 343
\][/tex]

[tex]\[
f(3) = \frac{343}{7}
\][/tex]

4. Perform the division:
Divide 343 by 7 to simplify the expression.

[tex]\[
343 \div 7 = 49
\][/tex]

The final answer is [tex]\( f(3) = 49 \)[/tex].

Therefore, the correct choice is B. 49.