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

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