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

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