There are 1 questions in this calculation: for each question, the 4 derivative of ln is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ 4th\ derivative\ of\ function\ ln + {(f(x))}^{2}\ with\ respect\ to\ ln：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = ln + f^{2}x^{2}\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( ln + f^{2}x^{2}\right)}{dln}\\=&1 + 0\\=&1\\\\ &\color{blue}{The\ second\ derivative\ of\ function:} \\&\frac{d\left( 1\right)}{dln}\\=&0\\\\ &\color{blue}{The\ third\ derivative\ of\ function:} \\&\frac{d\left( 0\right)}{dln}\\=&0\\\\ &\color{blue}{The\ 4th\ derivative\ of\ function:} \\&\frac{d\left( 0\right)}{dln}\\=&0\\ \end{split}\end{equation} \]

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