Logarithmic Functions Graphing and Comparison

Logarithmic Functions Graphing and Comparison
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2014-06-20 04:37
In collections CCGPS AA Unit 4 Lesson 2
This example demonstrates graphing and comparing three pairs of logarithmic functions. It involves core math concepts like logarithmic function properties, graph translations, and asymptotes. GeoGebra commands and objects such as Sequence, LaTeX, TableText, Ray, and Text are used in construction. Suitable for high school mathematics teaching, helping students understand function graph transformations and property analysis.

GeoGebra Commands & Parameters

  1. Sequence(x = a, a, -7, -4, 0.5) → list1
  2. LaTeX("\textcolor{#000099}{f(x)=-\log x}\text{ and }\textcolor{#000099}{g(x)=\log x}") → pair1
  3. LaTeX("\textcolor{#000099}{h(x)=-\log_{2} {x}}\text{ and }\textcolor{#000099}{j(x)=\log_{2} {x}}") → pair2
  4. LaTeX("\text{Three pairs of logarithmic functions are provided. Graph each pair on one coordinate}\cr\text{plane. Then, use the graphs to identify and compare the asymptotes, intercepts,}\cr \text{domains, and ranges for each pair, as well as the shape and end behavior of each pair}\cr \text{of graphs.}") → problemtext
  5. LaTeX("\textcolor{#000099}{m(x)=-\ln x}\text{ and }\textcolor{#000099}{p(x)=\ln x}") → pair3
  6. TableText({{pair1}, {pair2}, {pair3}}, "l") → text1
  7. LaTeX("\text{Graph the first pair of functions on the same coordinate plane.}") → text2
  8. LaTeX("\textcolor{#FF0000}{f(x)=-\log x}") → ftext
  9. LaTeX("\textcolor{#006400}{g(x)=\log x}") → gtext
  10. LaTeX("\text{Compare the shapes and end behavior of the graphs.}") → text3
  11. LaTeX("\text{The line of reflection is the }\textcolor{#FF00FF}\text{x-axis}\text{.}") → text4
  12. LaTeX((((("\text{The shape and end behavior of the graph of }\textcolor{#FF0000}{" * ftext) * "}\text{ are inverted}\cr \text{from the shape and end behavior of the graph of }\textcolor{#006400}{") * gtext) * "}\text{. In}\cr \text{other words, the two graphs are reflections of each other.} ")) → text33
  13. LaTeX((((("\text{The graph of }\textcolor{#FF0000}{" * ftext) * "}\text{ decreases as }\textcolor{#000099}\text{x}\text{ approaches positive infinity.}\cr \text{The graph of }\textcolor{#006400}{") * gtext) * "}\text{ increases as }\textcolor{#000099}\text{x}\text{ approaches positive infinity.}")) → text5
  14. LaTeX("\text{Identify the two graphs’ asymptotes, intercepts, domains, and ranges.}") → text6
  15. LaTeX("\text{Since neither graph crosses the }\textcolor{#000099}\text{y-axis}\text{, both graphs have a vertical}\cr\text{asymptote at }\textcolor{#FF00FF}\text{x = 0}\text{.}") → text7
  16. LaTeX("\text{The graphs cross the }\textcolor{#000099}\text{x-axis}\text{ at the x-intercept }\textcolor{#000099}{\left(1, 0 \right)}\text{.}") → text8
  17. LaTeX("\text{Since the }\textcolor{#000099}{x-values}\text{ increase into positive infinity but never cross the}\cr\textcolor{#000099}{y-axis}\text{, this means they are never negative. Thus, we can determine the}\cr\text{domain of both graphs is }\textcolor{#000099}{x > 0}\text{.}") → text9
  18. Ray((0.1, 0), (1, 0)) → c
  19. LaTeX("\text{The range of both graphs is }{\textcolor{#000099}\text{all real numbers}\text{.}") → text10
  20. LaTeX("\text{Graph the second pair of functions together on a new coordinate plane.}") → text11
  21. LaTeX("\textcolor{#006400}{j(x)=\log_{2}{x}}") → jtext
  22. LaTeX("\textcolor{#FF0000}{h(x)=-\log_{2}{x}}") → htext
  23. LaTeX((((("\text{The graph of }\textcolor{#006400}{" * jtext) * "}\text{ and }\textcolor{#FF0000}{") * htext) * "}\text{ is shown.}")) → text111
  24. LaTeX("\text{Compare the shapes and end behavior of the second pair of graphs.}") → text12
  25. LaTeX((((("\text{The shape and end behavior of the graph of }{" * htext) * "}\text{ are inverted}\cr\text{from that of }{") * jtext) * "}\text{. In other words, each graph is a reflection of}\cr\text{the other over the }\textcolor{#FF00FF}\text{x-axis}\text{.}")) → text122
  26. LaTeX((((("\text{The graph of }{" * htext) * "}\text{ decreases as }\textcolor{#000099}\text{x}\text{ approaches positive infinity.}\cr \text{The graph of }{") * jtext) * "}\text{ increases as }\textcolor{#000099}\text{x}\text{ approaches positive infinity.}")) → text13
  27. LaTeX("\text{Identify the two graphs’ asymptotes, intercepts, domains, and ranges.}") → text14
  28. LaTeX("\text{There is a vertical asymptote at }{\textcolor{#FF00FF}\text{x = 0}\text{ for each graph.}") → text15
  29. LaTeX("\text{Both graphs cross the }\textcolor{#000099}\text{x-axis}\text{ at the x-intercept }\textcolor{#000099}{\left(1, 0\right)}\text{.}") → text16
  30. LaTeX("\text{The domain of both graphs is }\textcolor{#000099}\text{x > 0}\text{.}") → text17
  31. LaTeX("\text{Since the y-values are not limited, we can determine the range of each graph}\cr\text{is }\textcolor{#000099}\text{all real numbers}\text{.}") → text18
  32. LaTeX("\text{Graph the third pair of functions together on a new coordinate plane.}\cr \text{Compare the graphs’ shapes and end behavior.}") → text19
  33. LaTeX("\textcolor{#006400}{p(x)=\ln x}") → ptext
  34. LaTeX("\textcolor{#FF0000}{m(x)=-\ln x}") → mtext
  35. LaTeX((((("\text{The graph of }{" * ptext) * "}\text{ and }{") * mtext) * "}\text{ is shown.}")) → text20
  36. LaTeX((((("\text{The shape and end behavior of the graph of }{" * mtext) * "}\text{ are inverted}\cr \text{from that of }{") * ptext) * "}\text{; therefore, the graphs are reflections of one}\cr\text{another. The line of reflection is the }\textcolor{#FF00FF}\text{x-axis}\text{.}")) → text21
  37. LaTeX((((("\text{The graph of }{" * mtext) * "}\text{ decreases as }\textcolor{#000099}\text{x}\text{ approaches positive infinity.}\cr\text{The graph of }{") * ptext) * "}\text{ increases as }\textcolor{#000099}\text{x}\text{ approaches positive infinity.}")) → text22
  38. LaTeX((((("\text{Graph the given functions, }{" * ftext) * "}\text{ and }{") * gtext) * "}\text{, by hand or}\cr\text{using a graphing calculator. The result should resemble the following.}")) → textnew2
  39. LaTeX("\text{Use the graphs to identify the asymptotes, intercepts, domains, and}\cr \text{ranges of this third pair of functions.}") → text23
  40. LaTeX("\text{There is a vertical asymptote at }\textcolor{#FF00FF}\text{x = 0}\text{.}") → text24
  41. LaTeX("\text{The graphs cross the x-axis at the x-intercept }\textcolor{#000099}{\left(1, 0\right)}\text{.}") → text25
  42. LaTeX("\text{The domain of both graphs is }\textcolor{#000099}\text{x > 0}\text{.}") → text26
  43. LaTeX("\text{The range of both graphs is }\textcolor{#000099}\text{all real numbers}\text{.}") → text27
  44. LaTeX("\text{Summarize your findings.}") → text28
  45. LaTeX("\text{In summary, all three pairs of graphs have the same vertical asymptote}\cr\text{of }\textcolor{#FF00FF}\text{x = 0}\text{. In every case, the x-intercept is }\textcolor{#000099}{\left(1, 0\right)}\text{. The domain and range}\cr \text{for all three pairs are identical. The three pairs of functions}\cr\text{differ in the rate of increase or decrease as }\textcolor{#000099}\text{x}\text{ increases.}") → text29
  46. Text("Move the slider to solve the problem.") → text0

AI Drawing Prompt Reference

Graph three pairs of logarithmic functions and compare them. The first pair, f(x)=-logx and g(x)=logx, are symmetric about the x-axis, intersect at x=1, have vertical asymptotes at x=0, and domains/ranges of x>0 and all real numbers respectively. The second pair, h(x)=-log2x and j(x)=log2x, share the same properties. The third pair, m(x)=-lnx and p(x)=lnx, also share the same properties. All graphs increase or decrease on the positive x-axis and are mirror images of each other.
The prompt above was compiled from the original drawing commands and is for reference only.