On the New y by Feedback display we begin with an x of 0.25 in the absence of any better idea, and iterate the function y=g*x*(1-x) with a g value of 3.5. After you have iterated our function as long as you like at that initial value of x, use the mouse button to mark a new initial x and iterate again from that starting point.

As you can see, with a gain of 3.5 choosing a different initial x changes the trail of marks but not the final values.