Set 3: Exponential Functions (Intermediate)

Choice A is correct. Choice A is the correct answer. Analyze the function form. 1. Form: $y = ab^x + k$ where $k = -2$. 2. Asymptote: As $x \to \infty$, $(0.9)^x \to 0$, so $y \to 0 - 2 = -2$. 3. Conclusion: Horizontal asymptote is $y = -2$. Strategic Tip: The vertical shift $k$ determines the asymptote. Choice B is incorrect because 7 is the coefficient, not the asymptote. Choice C is incorrect because $b < 1$ means decreasing (decay). Choice D is incorrect because y-intercept is $7(1) - 2 = 5$, at $(0, 5)$.