Why do you think you need to use a for loop, just to define the variable x=127.0526? Where does 127.0256 come from anyway?
You do apparently want to loop 100 times, so you would want to use a for loop.
But what is the purpose of the iteration? Is this an iteration to solve for y==0, so a root finding problem? What iteration were you told to do? A fixed point iteration, perhaps? Or is this just an iteration where you plug the output, y, back into the function? In that case, it will very rapidly diverge to infinity.
