Final answer:
The function representing a reflection of f(x) = 4(1/2)^x across the x-axis is G(x) = -4(1/2)^x.
Step-by-step explanation:
The question is asking to determine the function G(x), which is a reflection of the function f(x) = 4(1/2)^x across the x-axis. To reflect a function across the x-axis, you multiply the output of the function by -1. Therefore, the reflected function G(x) will be G(x) = -f(x), which in this case is G(x) = -4(1/2)^x.
The correct answer is therefore (a) G(x) = -4(1/2)^x, as this represents the function after it has been reflected over the x-axis, where every y-value of the original function f(x) is multiplied by -1.