There are 1 questions in this calculation: for each question, the 3 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ third\ derivative\ of\ function\ 999{x}^{4}\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = 999x^{4}\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( 999x^{4}\right)}{dx}\\=&999*4x^{3}\\=&3996x^{3}\\\\ &\color{blue}{The\ second\ derivative\ of\ function:} \\&\frac{d\left( 3996x^{3}\right)}{dx}\\=&3996*3x^{2}\\=&11988x^{2}\\\\ &\color{blue}{The\ third\ derivative\ of\ function:} \\&\frac{d\left( 11988x^{2}\right)}{dx}\\=&11988*2x\\=&23976x\\ \end{split}\end{equation} \]

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