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

Your problem has not been solved here? Please take a look at the  hot problems ！