There are 1 questions in this calculation: for each question, the 1 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ 3cos(\frac{x}{3} - a)\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = 3cos(\frac{1}{3}x - a)\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( 3cos(\frac{1}{3}x - a)\right)}{dx}\\=&3*-sin(\frac{1}{3}x - a)(\frac{1}{3} + 0)\\=&-sin(\frac{1}{3}x - a)\\ \end{split}\end{equation} \]

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