There are 1 questions in this calculation: for each question, the 1 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ cos(2x + 1)d(2x + 1)\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = 2dxcos(2x + 1) + dcos(2x + 1)\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( 2dxcos(2x + 1) + dcos(2x + 1)\right)}{dx}\\=&2dcos(2x + 1) + 2dx*-sin(2x + 1)(2 + 0) + d*-sin(2x + 1)(2 + 0)\\=&2dcos(2x + 1) - 4dxsin(2x + 1) - 2dsin(2x + 1)\\ \end{split}\end{equation} \]

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