Question: Can't solve equation without returning _Z

Hi,

I'm dealing with an iterated function (logistic map) where f(x)=s*x*(1-x) where the s is a general parameter between 1 and 4 inclusive, and it's fourth return map, or f(f(f(f(x)))) or f^[4](x).

h:x->f(f(f(f(x))))

What I'm trying to do hinges on evaluating this:

solve(h(x)=x,x);

all *(1/s) as the important answer.

When I set a value for s, everything runs smoothly but getting a formula in terms of s is the goal and I don't know what to make of this as I'm very new to Maple and can only do the basics so far. I've tried expanding, simplifying, and using assumptions on s but nothing seems to work. Also, I didn't know how to tag this so sorry for any confusion.

Any tips or help would be greatly appreciated

-Dale