There are 1 questions in this calculation: for each question, the 4 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ 4th\ derivative\ of\ function\ x(x - 9)(x - 9)\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = x^{3} - 18x^{2} + 81x\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( x^{3} - 18x^{2} + 81x\right)}{dx}\\=&3x^{2} - 18*2x + 81\\=&3x^{2} - 36x + 81\\\\ &\color{blue}{The\ second\ derivative\ of\ function:} \\&\frac{d\left( 3x^{2} - 36x + 81\right)}{dx}\\=&3*2x - 36 + 0\\=&6x - 36\\\\ &\color{blue}{The\ third\ derivative\ of\ function:} \\&\frac{d\left( 6x - 36\right)}{dx}\\=&6 + 0\\=&6\\\\ &\color{blue}{The\ 4th\ derivative\ of\ function:} \\&\frac{d\left( 6\right)}{dx}\\=&0\\ \end{split}\end{equation} \]

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