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

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