Derivative as a function



--- Albert Reiner <areiner@tph.tuwien.ac.at> wrote:

> >  (%i1) f(x) := x^2$
> >  
> >  (%i2) df(x) := ''(diff(f(x), x));
> ...
> > Note that df(x) := ''diff(f(x),x)$ doesn't work.
> 
> I find this extremely surprising.  Can someone explain why $ does not
> work, whereas ; does?  So far I thought that the only difference was
> whether the result of the evaluation is displayed or not.

Oh, sorry. The comparison is ''(diff(...)) and ''diff(...) --
I suppose '' applies to diff instead of the output of diff
in the second case.

Hope this helps,
Robert Dodier


		
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