7

Set 7: Exponential Functions (Advanced)

Explanation

Answer: A

For f(x)=100(3)xf(x) = 100(3)^x, as xx approaches negative infinity, f(x)f(x) approaches what value?

A.

0

✓ Correct
B.

100

C.

3

D.

Negative infinity

Detailed Explanation

Choice A is correct. Choice A is the correct answer. Analyze the limit as xx \to -\infty. 1. Negative Exponent: As xx \to -\infty, (3)x=13x0(3)^x = \frac{1}{3^{|x|}} \to 0. 2. Function: f(x)=100(3)x100(0)=0f(x) = 100(3)^x \to 100(0) = 0. 3. Asymptote: The horizontal asymptote is y=0y = 0 (x-axis). Strategic Tip: For exponential growth (b>1b > 1), the function approaches 0 as xx \to -\infty. Choice B is incorrect because 100 is the value at x=0x=0, not the limit. Choice C is incorrect because 3 is the base. Choice D is incorrect because the function approaches 0, not -\infty.

Key Steps:

The correct answer is 0

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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