Questions: Consider the function f(x)=(1/6)^x
a. Graph the function.
b. Equation of the asymptote:
c. Domain in interval notation:
d. Range in interval notation:
Transcript text: Consider the function $f(x)=\left(\frac{1}{6}\right)^{x}$
a. Graph the function.
b. Equation of the asymptote: $\square$
c. Domain in interval notation: $\square$
d. Range in interval notation: $\square$
Solution
Solution Steps
Step 1: Find the horizontal asymptote
The horizontal asymptote of an exponential function of the form $f(x) = ab^x + c$ is $y = c$. In this case, $f(x) = (\frac{1}{6})^x$ which can be rewritten as $f(x) = 1(\frac{1}{6})^x + 0$. Therefore the horizontal asymptote is $y = 0$.
Step 2: Find two points on the graph
We can find two points by substituting $x$ values into the function.
When $x=0$, $f(0) = (\frac{1}{6})^0 = 1$. So one point is $(0, 1)$.
When $x=-1$, $f(-1) = (\frac{1}{6})^{-1} = 6$. So another point is $(-1, 6)$.
Step 3: Determine the domain
Exponential functions of the form $f(x) = ab^x$ have a domain of all real numbers. Therefore, the domain in interval notation is $(-\infty, \infty)$.
Step 4: Determine the range
Since the horizontal asymptote is $y=0$ and the base $b = \frac{1}{6}$ is between 0 and 1, the function is decreasing and the range is all positive real numbers, excluding 0. In interval notation, the range is $(0, \infty)$.
Final Answer:
a. The graph should pass through the points $(0, 1)$ and $(-1, 6)$, with a horizontal asymptote at $y=0$.
b. $y=0$
c. $(-\infty, \infty)$
d. $(0, \infty)$