Linear Equations & Optimization Demo

Linear Equations & Optimization Demo
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2017-08-06 22:10
This example demonstrates the graphical solution of linear equations and optimization problems using GeoGebra. Core math concepts include linear equations, logarithmic functions, linear programming, probability & statistics, and linear regression. Construction highlights from the summary involve commands like LaTeX, Corner, If, Zip, Append, TableText, and objects such as timeDepthratio, depthratio, stepMax, stepper, steps, etc., making it suitable for high school and above for understanding complex mathematical model construction and visualization.

GeoGebra Commands & Parameters

  1. LaTeX(steps) → counter
  2. LaTeX("\text{Move the slider to solve the problem}") → text0
  3. LaTeX("\text{Use the buttons below to return to the original problem or}\cr\text{randomly generate a similar practice problem.}") → RandomizationText
  4. Corner(1) → A
  5. Corner(3) → B
  6. If(direction ≟ 0, "filling", "emptying") → directionWord
  7. LaTeX((("\text{Jeremy is " * directionWord) * " his swimming pool for the summer. The following table shows the}\cr\text{depth of the water in the pool after }\textcolor{#000099}{x}\text{ number of minutes. Determine the key features}\cr\text{of this function.}")) → Problem
  8. Zip((timeratio * k), k, intervalScales) → TimeIntervals
  9. Append(0, Sequence[Sum[TimeIntervals, k], k, 1, 8]) → Times
  10. Zip((depthratio * k), k, intervalScales) → DepthIntervals
  11. Append(0, Sequence[Sum[DepthIntervals, k], k, 1, 8]) → DepthValues
  12. If(direction ≟ 0, DepthValues, Append[DepthValues(9), Sequence[DepthValues(9) - Sum[DepthIntervals, k], k, 1, 8, 1]]) → Depths
  13. LaTeX("\text{Determine whether the function is linear.}") → text1
  14. LaTeX("\text{Identify the intercepts of the function based on the information in the table.}") → text3
  15. TableText({Append[LaTeX["\text{Minutes (}\textcolor{#000099}{x}\text{)}"], Times], Append[LaTeX["\text{Depth in cm (}\textcolor{#000099}{y}\text{)}"], Depths]}) → ProblemData
  16. LaTeX((((((((("\text{The function intersects the }\textcolor{#000099}{y}\text{-axis at the point }\textcolor{#000099}{" * Yintercept) * "}\text{ as indicated in the table,}\cr\text{and it also intersects the }\textcolor{#000099}{x}\text{-axis at }\textcolor{#000099}{") * Xintercept) * "}\text{.}\cr\text{}\cr\text{Therefore, the }\textcolor{#000099}{y}\text{-intercept is }\textcolor{#000099}{") * Yintercept) * "}\text{ and the }\textcolor{#000099}{x}\text{-intercept is }\textcolor{#000099}{") * Xintercept) * "}\text{.}")) → text4
  17. LaTeX("\text{Determine whether the function is increasing or decreasing.}") → text5
  18. If(direction ≟ 0, "increasing", "decreasing") → functionWord
  19. If(direction ≟ 0, "increase", "decrease") → yWord
  20. LaTeX((((("\text{As the }\textcolor{#000099}{x}\text{-values increase, the }\textcolor{#000099}{y}\text{-values " * yWord) * ". Therefore, the function is}\cr\text{") * functionWord) * ".}")) → text6
  21. LaTeX("\text{Determine where the function is positive and negative.}") → text7
  22. If(direction ≟ 0, ">", "<") → relationSign
  23. If(direction ≟ 0, 0, Times(9)) → keyX
  24. If(direction ≟ 0, "greater", "less than") → relationWord
  25. LaTeX("\text{Determine the relative minimum and maximum of the function.}") → text9
  26. If(direction ≟ 0, LaTeX["\text{whatever time Jeremy stops filling the pool, or}\cr\text{when the pool starts overflowing. The problem did not specify when this would be.}"], LaTeX[(("\textcolor{#000099}{" * Yintercept) * "}\text{ before the pool begins to empty.}")]) → relMax
  27. If(direction ≟ 0, (0, 0), (Times(9), 0)) → relMin
  28. LaTeX((("\text{The relative maximum occurs at " * relMax) * "}")) → text10b
  29. LaTeX("\text{Identify the domain of the function.}") → text11
  30. LaTeX((("\text{We can see from the table that the differences for }\textcolor{#000099}{y}\text{ are always }\textcolor{#000099}{\frac{1}{" * timeDepthratio) * "}}\text{ the}\cr\text{differences in }\textcolor{#000099}{x}\text{, indicating that the rate of change is constant. Therefore, the}\cr\text{scenario described here is linear.}")) → text2
  31. LaTeX((((((((("\text{The }\textcolor{#000099}{y}\text{-values are positive for all }\textcolor{#000099}{x}\text{-values " * relationWord) * " than }\textcolor{#000099}{") * keyX) * "}\text{. Therefore, the}\cr\text{function is positive when }\textcolor{#000099}{x ") * relationSign) * " ") * keyX) * "}\text{.}\cr\text{}\cr\text{The }\textcolor{#000099}{y}\text{-values are never negative in this scenario. Therefore, the function is never}\cr\text{negative. }")) → text8
  32. LaTeX((("\text{The relative minimum occurs at }\textcolor{#000099}{" * relMin) * "}\text{, because there cannot be a negative}\cr\text{amount of water in the pool.}")) → text10
  33. LaTeX((((("\text{The least }\textcolor{#000099}{x}\text{-value is }\textcolor{#000099}{0}\text{, the time when Jeremy starts " * directionWord) * " the pool. The}\cr\text{greatest }\textcolor{#000099}{x}\text{-value is whatever time Jeremy stops ") * directionWord) * " the pool. Additionally, }\cr\textcolor{#000099}{x}\text{ can be any real number because time is continuous.}")) → text12