Question

Which function represents g(x), a reflection of f(x) =4(1/2)x across the x-axis?
g(x) = −4(2)x
g(x) = 4(2)−x
g(x) = −4(1/2)x
g(x) = 4(1/2)-x

Answer 1

Correct answer is C -I just took the test

Answer 2

Answer: Hello mate!

we have the function f(x) = 4(1/2)x, and we want to reflex it over the x-axis.

you can see in the graph that the reflex over this axis changes the sign of f(x) in all the points (where f(0) = 4, g(0) = -4, f(1) = 2, g(1) = -2, and so on), then the reflex, g(x) is equal to -f(x)

now we have:

g(x) = -f(x) = - 4(1/2)x

then the right answer is the third option:

g(x) = -4(1/2)x