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

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