There are 1 questions in this calculation: for each question, the 2 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ second\ derivative\ of\ function\ ln(tan(x))\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( ln(tan(x))\right)}{dx}\\=&\frac{sec^{2}(x)(1)}{(tan(x))}\\=&\frac{sec^{2}(x)}{tan(x)}\\\\ &\color{blue}{The\ second\ derivative\ of\ function:} \\&\frac{d\left( \frac{sec^{2}(x)}{tan(x)}\right)}{dx}\\=&\frac{-sec^{2}(x)(1)sec^{2}(x)}{tan^{2}(x)} + \frac{2sec^{2}(x)tan(x)}{tan(x)}\\=&\frac{-sec^{4}(x)}{tan^{2}(x)} + 2sec^{2}(x)\\ \end{split}\end{equation} \]

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