There are 1 questions in this calculation: for each question, the 1 derivative of t is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ lsin(-69 + w*13t) + lsin(wt)\ with\ respect\ to\ t：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = lsin(13wt - 69) + lsin(wt)\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( lsin(13wt - 69) + lsin(wt)\right)}{dt}\\=&lcos(13wt - 69)(13w + 0) + lcos(wt)w\\=&13lwcos(13wt - 69) + lwcos(wt)\\ \end{split}\end{equation} \]

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