绝对值函数求逆及定义域值域分析

绝对值函数求逆及定义域值域分析
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2014-08-06 01:41
①本范例演示了如何求绝对值函数f(x)=|x+2|的逆函数,并分析其定义域与值域;②涉及核心数学概念包括绝对值函数、逆函数、定义域、值域;③作图要点:使用LaTeX命令显示数学表达式,If条件判断,TableText创建表格文本,stepMax、stepper、steps、counter等对象实现分步演示,f、g_1、g_2等对象表示函数图像,mirror实现镜像变换;④适合高中数学学生学习和理解函数性质及逆函数概念。

GeoGebra 命令及参数

  1. LaTeX(steps) → counter
  2. LaTeX((("\textcolor{#000099}{f(x)=" * f) * "}")) → Problem
  3. LaTeX("\text{Write the inverse of the function and simplify it.}") → text4
  4. If(a ≟ 1, LaTeX["f(x)"], If[a ≟ -1, LaTeX["-f(x)"], LaTeX[(a * "f(x)")]]) → first
  5. If(b ≟ 0, "", If[b < 0, LaTeX[("-" * abs(b))], LaTeX[("+" * b)]]) → second
  6. If(a ≟ 1, LaTeX["f^{-1}(x)"], If[a ≟ -1, LaTeX["-f^{-1}(x)"], LaTeX[(a * "f^{-1}(x)")]]) → firstb
  7. LaTeX("\text{Solve for }\textcolor{#006633}{f^{-1}(x)}.") → text6
  8. LaTeX("\text{Handle the absolute value by working with two cases.}") → text7
  9. LaTeX("\text{Determine the domains and ranges of }\textcolor{#000099}{f(x)}\text{ and }\textcolor{#006633}{f^{-1}(x)}.") → text1
  10. LaTeX("\text{State the final results.}") → text9
  11. LaTeX("\text{Graph both functions and their inverses together.}") → text14
  12. LaTeX("\text{Use the buttons below to return to the original problem or}\cr\text{randomly generate a similar practice problem.}") → text13
  13. TableText({{LaTeX[(("\textcolor{#000099}{f(x)=" * f) * "}")], LaTeX["\text{Original function}"]}, {LaTeX[((("\textcolor{#006633}{x=\left|" * first) * second) * "\right|}")], LaTeX["\text{Switch the variables.}"]}, {LaTeX[((("\textcolor{#006633}{x=\left|" * firstb) * second) * "\right|}")], LaTeX["\text{Since this defines the inverse function, change to }\textcolor{#006633}{f^{-1}(x)}."]}}) → text5
  14. LaTeX("\text{In order for a function to have an inverse, the function must be one-to-one.}\cr \text{Since absolute value functions are V-shaped, the domain of }\textcolor{#000099}{f(x)}\text{ needs to be restricted.}\cr \text{The range(s) of }\textcolor{#006633}{f^{-1}(x)}\text{ will be the restricted domain(s) of }\textcolor{#000099}{f(x)}.\cr \text{The domain of }\textcolor{#006633}{f^{-1}(x)}\text{ will be the range of }\textcolor{#000099}{f(x)}.") → text2
  15. TableText({{LaTeX[""], LaTeX["\textcolor{#000099}{f(x)}"], LaTeX["\textcolor{#006633}{f^{-1}(x)}"]}, {LaTeX["\text{Domain:}"], LaTeX["\text{all real numbers;}"], LaTeX["\textcolor{#006633}{[0,+\infty)}"]}, {LaTeX[""], LaTeX[(("\text{split domain where }\textcolor{#000099}{" * Simplify[(a * x) + b]) * "=0}")], LaTeX["\textcolor{#006633}{}"]}, {LaTeX[""], LaTeX["\text{ to get restricted domains where }"], LaTeX["\textcolor{#006633}{}"]}, {LaTeX[""], LaTeX["\text{ }\textcolor{#000099}{f(x)}\text{ is one-to-one}"], LaTeX["\textcolor{#006633}{}"]}, {LaTeX[""], LaTeX[(((("\textcolor{#000099}{(-\infty," * Simplify[((-b)) / a]) * "]}\text{ and }\textcolor{#000099}{[") * Simplify[((-b)) / a]) * ",+\infty)}")], LaTeX["\textcolor{#006633}{}"]}, {LaTeX["\text{Range:}"], LaTeX["\text{The vertex of the function is at}"], LaTeX[(((("\textcolor{#006633}{(-\infty," * Simplify[((-b)) / a]) * "]}\text{ and }\textcolor{#006633}{[") * Simplify[((-b)) / a]) * ",+\infty)}")]}, {LaTeX[""], LaTeX["\text{ }\textcolor{#000099}{x=0}\text{ and the function opens up.}"], LaTeX[""]}, {LaTeX[""], LaTeX["\textcolor{#000099}{[0,+\infty)}"], LaTeX[""]}}) → text3
  16. TableText({{LaTeX[((("\textcolor{#006633}{x=" * firstb) * second) * "}")], LaTeX["\text{Set up two cases.}"], LaTeX[((("\textcolor{#006633}{-x=" * firstb) * second) * "}")]}, {LaTeX[(((("\textcolor{#006633}{" * Simplify[x - b]) * "=") * firstb) * "}")], LaTeX[(("\text{Subtract }\textcolor{#006633}{" * b) * "}\text{ from both sides.}")], LaTeX[(((("\textcolor{#006633}{" * Simplify[(-x) - b]) * "=") * firstb) * "}")]}, {LaTeX[(((("\textcolor{#006633}{\frac{" * Simplify[x - b]) * "}{") * a) * "}=f^{-1}(x)}")], LaTeX[(("\text{Divide both sides by }\textcolor{#006633}{" * a) * "}.")], LaTeX[(((("\textcolor{#006633}{\frac{" * Simplify[(-x) - b]) * "}{") * a) * "}=f^{-1}(x)}")]}, {LaTeX[(("\textcolor{#006633}{f^{-1}(x)=" * g_1) * "}")], LaTeX["\text{Simplify and use the Symmetric Property of Equality.}"], LaTeX[(("\textcolor{#006633}{f^{-1}(x)=" * g_2) * "}")]}}) → text8
  17. LaTeX((((((((((((("\text{On the restricted domain }\textcolor{#000099}{[" * Simplify[((-b)) / a]) * ",+\infty)}\text{, the inverse of }\textcolor{#000099}{f(x)=") * f) * "}\text{ is }\textcolor{#006633}{f^{-1}(x)=") * g_1) * "}\text{ where }\textcolor{#006633}{[0,+\infty)}\text{.}\cr \text{On the restricted domain }\textcolor{#000099}{(-\infty,") * Simplify[((-b)) / a]) * "]}\text{, the inverse of }\textcolor{#000099}{f(x)=") * f) * "}\text{ is }\textcolor{#006633}{f^{-1}(x)=") * g_2) * "}\text{ where }\textcolor{#006633}{[0,+\infty)}. ")) → text10
  18. LaTeX((("\text{Graph the function on the restricted domain }\cr\textcolor{#000099}{[" * Simplify[((-b)) / a]) * ",+\infty)}\text{ and graph its inverse.}")) → text11
  19. LaTeX((("\text{Graph the function on the restricted domain }\cr\textcolor{#000099}{(-\infty," * Simplify[((-b)) / a]) * "]}\text{ and graph its inverse.}")) → text12

AI 绘图提示语参考

画绝对值函数f(x)=|x+2|及其反函数的图像,并分析它们的定义域和值域。首先,画出V形的绝对值函数图像,然后确定其定义域和值域。接着,求出反函数,并分别在两个区间内画出反函数的图像。最后,将原函数和反函数的图像绘制在同一坐标系中,并标注它们的定义域和值域。
以上提示语为根据原始绘图命令整理而来,仅供参考。