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

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