I have a basic question on how to take derivatives using Math Palettes:
I would like to get the derivative of
cos(k*x - w*t) with respect to
D[Cos[k*x - w*t], x] successfully returns
k Sin[t w - k x], but I also want to learn to do it using Math Palette. When I use the tool like I did below, I cannot do it. How do I fix this? What am I doing wrong?