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Activity 9.7 Making Graphs

Let’s put it all together and produce some graphs.

Exercises Exercises

Exercise Group.

Consider the function \(\fe{f}{x}=\frac{8x^2-8}{(2x-4)^2}\text{.}\)

1.

Evaluate each of the following limits: \(\lim\limits_{x\to\infty}\fe{f}{x}\text{,}\) \(\lim\limits_{x\to-\infty}\fe{f}{x}\text{,}\) \(\lim\limits_{x\to2^{-}}\fe{f}{x}\text{,}\) and \(\lim\limits_{x\to2^{+}}\fe{f}{x}\text{.}\)

2.

What are the horizontal and vertical asymptotes for \(f\)’s graph?

3.

What are the horizontal and vertical intercepts for \(f\)’s graph?

4.

Use the formulas \(\fe{\fd{f}}{x}=\frac{4(1-2x)}{(x-2)^3}\) and \(\fe{\sd{f}}{x}=\frac{4(4x+1)}{(x-2)^4}\) to help you accomplish each of the following.
  • State the critical numbers of \(f\text{.}\)
  • Create well-documented increasing/decreasing and concavity tables for \(f\text{.}\)
  • State the local minimum, local maximum, and inflection points on \(f\text{.}\) Make sure that you explicitly address all three types of points whether they exist or not.

5.

Graph \(y=\fe{f}{x}\) onto FigureΒ 9.7.1. Choose a scale that allows you to clearly illustrate each of the features found in ExercisesΒ 9.7.1–9.7.4. Label all axes and asymptotes well and write the coordinates of each local extreme point and inflection point next to the point.
Figure 9.7.1. \(y=\fe{f}{x}\)

7.

Following analysis similar to that implied in ExercisesΒ 9.7.1–9.7.5 graph the function
\begin{equation*} \fe{g}{t}=\frac{1}{(e^t+4)^2}\text{.} \end{equation*}
Use the formulas
\begin{equation*} \fe{\fd{g}}{t}=\frac{-2e^t}{(e^t+4)^3}\qquad\fe{\sd{g}}{t}=\frac{4e^t(e^t-2)}{(e^t+4)^4}\text{.} \end{equation*}
Check your graph using a graphing calculator.
Figure 9.7.2. \(y=\fe{g}{x}\)