I am having trouble understanding the following question:
There is a scalar field f(r) depending on r = (x,y,z) through r = .
Show that r
I know that grad f is normally each partial derivative i.e. (df/dx, df/dy, df/dz) but how do I calculate it when it only has r as the parameter?
I'm also unsure as to how you would calculate f' in this situation, as I can't see an equation to differentiate.
Anything that helps me understand this better is greatly appreciated.