find_root



Hello, may be someone can help me with using find_root function as an ordinary 
function. Here is what I was trying to do:

g(a) := find_root(f(x,a),x,xmin,xmax);
g(0.5); --> should give the appropriate numerical solution (this works with 
the above definition)
g(z+z); --> should give g(2z),
at(%,z=0.25); --> should give the number immidiately
plot2d(g(z),[z,zmin,zmax]); --> should work

Somehow there seems to be nothing in the documentation on it (I tried 
everything I could imagine with ' and '' and was trying to make a wrapper 
that returns just a symbol when the argument is not a number, but I didn't 
succeed to make everything work.) I.e. I'd like to have a function just like 
an ordinary one, say, sin(x).

Andrei.