There are 1 questions in this calculation: for each question, the 1 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ \frac{0.42*180}{(cos(x) + 0.42sin(x))}\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( \frac{75.6}{(cos(x) + 0.42sin(x))}\right)}{dx}\\=&75.6(\frac{-(-sin(x) + 0.42cos(x))}{(cos(x) + 0.42sin(x))^{2}})\\=&\frac{75.6sin(x)}{(cos(x) + 0.42sin(x))(cos(x) + 0.42sin(x))} - \frac{31.752cos(x)}{(cos(x) + 0.42sin(x))(cos(x) + 0.42sin(x))}\\ \end{split}\end{equation} \]

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