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Set 9: Exponential Functions (Intermediate)

Explanation

Answer: A

Which statement about exponential functions y=abxy = ab^x is always true?

A.

The domain is all real numbers

✓ Correct
B.

The range includes negative numbers

C.

The graph has an x-intercept

D.

The function is linear

Detailed Explanation

Choice A is correct. Choice A is the correct answer. Analyze properties of exponential functions. 1. Domain: You can raise bb to any real power, so domain is all real numbers ✓ 2. Range: For a>0a > 0 and b>0b > 0, output is always positive (no x-intercept). 3. Shape: Exponential functions curve, not straight. Strategic Tip: Standard exponential y=abxy = ab^x (with a,b>0a, b > 0) never touches the x-axis. Choice B is incorrect because abx>0ab^x > 0 for all xx when a,b>0a, b > 0. Choice C is incorrect because the graph approaches but never reaches y=0y = 0. Choice D is incorrect because exponential functions are not linear.

Key Steps:

The correct answer is The domain is all real numbers

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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