There are 1 questions in this calculation: for each question, the 1 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ cos(0.68 - x) + 0.4sin(0.68 - x)\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = cos(-x + 0.68) + 0.4sin(-x + 0.68)\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( cos(-x + 0.68) + 0.4sin(-x + 0.68)\right)}{dx}\\=&-sin(-x + 0.68)(-1 + 0) + 0.4cos(-x + 0.68)(-1 + 0)\\=&sin(-x + 0.68) - 0.4cos(-x + 0.68)\\ \end{split}\end{equation} \]

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