There are 1 questions in this calculation: for each question, the 1 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ \frac{sqrt(9 + {x}^{2})}{13} + x\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = \frac{1}{13}sqrt(x^{2} + 9) + x\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( \frac{1}{13}sqrt(x^{2} + 9) + x\right)}{dx}\\=&\frac{\frac{1}{13}(2x + 0)*\frac{1}{2}}{(x^{2} + 9)^{\frac{1}{2}}} + 1\\=&\frac{x}{13(x^{2} + 9)^{\frac{1}{2}}} + 1\\ \end{split}\end{equation} \]

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