There are 1 questions in this calculation: for each question, the 1 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ 9.8(cos(0.785 - x) - 0.3sin(0.785 - x)) + 0.007\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = 9.8cos(-x + 0.785) - 2.94sin(-x + 0.785) + 0.007\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( 9.8cos(-x + 0.785) - 2.94sin(-x + 0.785) + 0.007\right)}{dx}\\=&9.8*-sin(-x + 0.785)(-1 + 0) - 2.94cos(-x + 0.785)(-1 + 0) + 0\\=&9.8sin(-x + 0.785) + 2.94cos(-x + 0.785)\\ \end{split}\end{equation} \]

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