8

Set 10: Exponential Functions (Advanced)

Explanation

Answer: A

For the function f(x)=200(3)xf(x) = 200(3)^x, what is f(1)f(-1)?

A.

2003\frac{200}{3}

✓ Correct
B.

600-600

C.

197197

D.

600600

Detailed Explanation

Choice A is correct. Choice A is the correct answer. Evaluate at x=1x = -1. 1. Substitute: f(1)=200(3)1f(-1) = 200(3)^{-1}. 2. Negative Exponent: (3)1=13(3)^{-1} = \frac{1}{3}. 3. Calculate: 20013=2003200\cdot \frac{1}{3} = \frac{200}{3}. Strategic Tip: Negative exponent: bx=1bxb^{-x} = \frac{1}{b^x}. Choice B is incorrect because negative exponent doesn't make the result negative. Choice C is incorrect because this suggests subtraction (2003200- 3). Choice D is incorrect because this is 200×3200\times 3, not division.

Key Steps:

The correct answer is 2003\frac{200}{3}

Why others are wrong:
B: Choice B is incorrect and may result from a calculation error.
C: Choice C is incorrect and may result from a calculation error.
D: Choice D is incorrect and may result from a calculation error.

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