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

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