Exponential Function 01E291
1. The problem asks to analyze the function $f(x) = 16^{9-x}$.
2. This is an exponential function where the base is 16 and the exponent is $9-x$.
3. Recall the exponential function formula: $f(x) = a^{bx+c}$ where $a>0$ and $a \neq 1$.
4. Here, $a=16$, $b=-1$, and $c=9$.
5. The function decreases because the exponent has a negative coefficient for $x$.
6. To understand the behavior, rewrite the function as:
$$f(x) = 16^{9-x} = 16^9 \cdot 16^{-x} = 16^9 \cdot \left(\frac{1}{16}\right)^x$$
7. This shows the function is a decreasing exponential function scaled by $16^9$.
8. The domain of $f(x)$ is all real numbers $(-\infty, \infty)$.
9. The range is $(0, \infty)$ because exponential functions with positive bases are always positive.
10. The function has no intercepts with the x-axis because it never equals zero.
11. The y-intercept is at $x=0$:
$$f(0) = 16^{9-0} = 16^9$$
12. The graph will approach zero as $x \to \infty$ and grow very large as $x \to -\infty$.
Final answer: The function $f(x) = 16^{9-x}$ is a decreasing exponential function with domain $(-\infty, \infty)$ and range $(0, \infty)$, y-intercept at $(0, 16^9)$, and no x-intercepts.