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

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