Determine if the function is an exponential function.  
If so, identify the power & base, then evaluate for $x=4$ .
$f\left(x\right)=\left(\frac12\right)^{x}$

• A. Exponential function, $f\left(4\right)=\frac{1}{16}$
• B. Exponential function, $f\left(4\right)=-16$
• C. Not an exponential function

Answer: (A)

Verified step by step guidance

1. Identify the general form of an exponential function, which is f(x) = a * b^x, where a is a constant, b is the base, and x is the exponent.
2. Examine the given function f(x) = (1/2)^x. Notice that it matches the form of an exponential function with a = 1 and b = 1/2.
3. Since the function is in the form f(x) = b^x, it is indeed an exponential function. Here, the base b is 1/2.
4. To evaluate the function at x = 4, substitute x with 4 in the function: f(4) = (1/2)^4.
5. Calculate (1/2)^4 by multiplying 1/2 by itself four times: (1/2) * (1/2) * (1/2) * (1/2).