There are 1 questions in this calculation: for each question, the 1 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ {cos(3x)}^{4}\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = cos^{4}(3x)\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( cos^{4}(3x)\right)}{dx}\\=&-4cos^{3}(3x)sin(3x)*3\\=&-12sin(3x)cos^{3}(3x)\\ \end{split}\end{equation} \]

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