1. **State the problem:**
Graph the function $f(x) = -2 \left(\frac{1}{5}\right)^x$ and identify the asymptote.
2. **Formula and rules:**
The function is an exponential function of the form $f(x) = a b^x$ where $a = -2$ and $b = \frac{1}{5}$.
- Since $0 < b < 1$, this is exponential decay.
- The negative sign reflects the graph below the x-axis.
- The horizontal asymptote for $f(x) = a b^x$ when $b > 0$ is the line $y=0$ (the x-axis).
3. **Plot points:**
Calculate $f(0)$ and $f(1)$:
$$f(0) = -2 \left(\frac{1}{5}\right)^0 = -2 \times 1 = -2$$
$$f(1) = -2 \left(\frac{1}{5}\right)^1 = -2 \times \frac{1}{5} = -\frac{2}{5}$$
4. **Asymptote:**
The asymptote is the x-axis, which is a horizontal line $y=0$.
5. **Summary:**
- The graph approaches $y=0$ but never crosses it.
- The points $(0, -2)$ and $(1, -\frac{2}{5})$ lie on the curve.
- The graph is an exponential decay reflected below the x-axis.
**Final answer:** The asymptote is horizontal, $y=0$.
Exponential Decay E4B7D6
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