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

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