There are 1 questions in this calculation: for each question, the 1 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ e^{t} - \frac{e^{-t}}{e^{t}} + e^{-t}\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = - \frac{e^{-t}}{e^{t}} + e^{t} + e^{-t}\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( - \frac{e^{-t}}{e^{t}} + e^{t} + e^{-t}\right)}{dx}\\=& - \frac{e^{-t}*0}{e^{t}} - \frac{e^{-t}*-e^{t}*0}{e^{{t}*{2}}} + e^{t}*0 + e^{-t}*0\\=&0\\ \end{split}\end{equation} \]

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