Dan Bron wrote: > Nor is the original math notation itself without flaw. I notice that the > left-hand side of the equation is written using function composition: > > (f o g)' > > but the right-hand side is written with nested function calls: > > f'(g(x)) > > which is inconsistent. I might've written the equation thus: > > (f o g)'(x) = (f' o g)(x) * g'(x)
The prime notation is not really the best mathematical notation for transparently expressing the chain rule: Leibniz notation is better: dy dy du -- = -- -- dx du dx Best wishes, John ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
