There are 1 questions in this calculation: for each question, the 1 derivative of x is calculated.
    Note that variables are case sensitive.
\[ \begin{equation}\begin{split}[1/1]Find\ the\ first\ derivative\ of\ function\ 50cos(45 - x) + 50cos(x)\ with\ respect\ to\ x：\\\end{split}\end{equation} \]\[ \begin{equation}\begin{split}\\Solution:&\\ &Primitive\ function\ = 50cos(-x + 45) + 50cos(x)\\&\color{blue}{The\ first\ derivative\ function：}\\&\frac{d\left( 50cos(-x + 45) + 50cos(x)\right)}{dx}\\=&50*-sin(-x + 45)(-1 + 0) + 50*-sin(x)\\=&50sin(-x + 45) - 50sin(x)\\ \end{split}\end{equation} \]

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