There are 1 questions in this calculation: for each question, the 1 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ cos(xe^{7x})\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( cos(xe^{7x})\right)}{dx}\\=&-sin(xe^{7x})(e^{7x} + xe^{7x}*7)\\=&-e^{7x}sin(xe^{7x}) - 7xe^{7x}sin(xe^{7x})\\ \end{split}\end{equation} \]

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