There are 1 questions in this calculation: for each question, the 2 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ second\ derivative\ of\ function\ (2x){\frac{1}{({x}^{2} + 9)}}^{\frac{1}{2}}\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = \frac{2x}{(x^{2} + 9)^{\frac{1}{2}}}\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( \frac{2x}{(x^{2} + 9)^{\frac{1}{2}}}\right)}{dx}\\=&2(\frac{\frac{-1}{2}(2x + 0)}{(x^{2} + 9)^{\frac{3}{2}}})x + \frac{2}{(x^{2} + 9)^{\frac{1}{2}}}\\=&\frac{-2x^{2}}{(x^{2} + 9)^{\frac{3}{2}}} + \frac{2}{(x^{2} + 9)^{\frac{1}{2}}}\\\\ &\color{blue}{The\ second\ derivative\ of\ function:} \\&\frac{d\left( \frac{-2x^{2}}{(x^{2} + 9)^{\frac{3}{2}}} + \frac{2}{(x^{2} + 9)^{\frac{1}{2}}}\right)}{dx}\\=&-2(\frac{\frac{-3}{2}(2x + 0)}{(x^{2} + 9)^{\frac{5}{2}}})x^{2} - \frac{2*2x}{(x^{2} + 9)^{\frac{3}{2}}} + 2(\frac{\frac{-1}{2}(2x + 0)}{(x^{2} + 9)^{\frac{3}{2}}})\\=&\frac{6x^{3}}{(x^{2} + 9)^{\frac{5}{2}}} - \frac{6x}{(x^{2} + 9)^{\frac{3}{2}}}\\ \end{split}\end{equation} \]

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