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

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