There are 1 questions in this calculation: for each question, the 2 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ second\ derivative\ of\ function\ -0.0026{x}^{3} + 0.0408{x}^{2} - 0.1891x + 18.808\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = -0.0026x^{3} + 0.0408x^{2} - 0.1891x + 18.808\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( -0.0026x^{3} + 0.0408x^{2} - 0.1891x + 18.808\right)}{dx}\\=&-0.0026*3x^{2} + 0.0408*2x - 0.1891 + 0\\=&-0.0078x^{2} + 0.0816x - 0.1891\\\\ &\color{blue}{The\ second\ derivative\ of\ function:} \\&\frac{d\left( -0.0078x^{2} + 0.0816x - 0.1891\right)}{dx}\\=&-0.0078*2x + 0.0816 + 0\\=&-0.0156x + 0.0816\\ \end{split}\end{equation} \]

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