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

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