There are 1 questions in this calculation: for each question, the 1 derivative of l is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ 35 + 8\ with\ respect\ to\ l：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = 43\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( 43\right)}{dl}\\=&0\\ \end{split}\end{equation} \]

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