Answer:
(c) f(x) = 500(5^x)
Step-by-step explanation:
An exponential function is one that has the independent variable (x) in the exponent. The initial value of an exponential function (or any function) is the value when x=0.
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You are looking for a function with x in the exponent, and with an initial value of 500. Eliminate answer choices that don't have x in the exponent. Evaluate the remaining choices for x=0 and see which gives you a value of 500.
f(x) = 100(5)^x ⇒ f(0) = 100·1 = 100 ≠ 500
f(x) = 100(x^5) . . . not an exponential function
f(x) = 500(5)^x ⇒ f(0) = 500·1 = 500 . . . . . the function you're seeking
f(x) = 500(x^2) . . . not an exponential function
