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

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