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

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