\[ \begin{flalign} f\left(x\right)=x^{2}&& \end{flalign} \] \[ \begin{flalign} g\left(x\right)=\frac{d}{dx}f\left(x\right)&& \end{flalign} \] \[ \begin{flalign} \left(a,f\left(a\right)\right)&& \end{flalign} \] \[ \begin{flalign} y-f\left(a\right)=g\left(a\right)\left(x-a\right)&& \end{flalign} \] \[ \begin{flalign} a=1　　\color{blue}-2\ \le\ a\ \le\ 2\ \text{の範囲で振動させる}&& \end{flalign} \] \[ \begin{flalign} b=\left[-20...20\right]　　\color{blue}← 包絡線を描くための準備&& \end{flalign} \] \[ \begin{flalign} y-f\left(\frac{b}{10}\right)=g\left(\frac{b}{10}\right)\left(x-\frac{b}{10}\right)&& \end{flalign} \]
　　　　

コピペ用テキストエリア（ Ctrl＋v で貼り付け ）：

f\left(x\right)=x^{2} g\left(x\right)=\frac{d}{dx}f\left(x\right) \left(a,f\left(a\right)\right) y-f\left(a\right)=g\left(a\right)\left(x-a\right) a=1 b=\left[-20...20\right] y-f\left(\frac{b}{10}\right)=g\left(\frac{b}{10}\right)\left(x-\frac{b}{10}\right)