Find the differential, $LaTeX: \displaystyle dy$ , of $LaTeX: \displaystyle y = e^{2 \cos{\left(x \right)}}$ .

The differential is given by $LaTeX: \displaystyle dy = f'(x)dx$ . Using the formula gives: $LaTeX: dy = - 2 e^{2 \cos{\left(x \right)}} \sin{\left(x \right)}\,dx$