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

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