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

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