I'm trying to build a simple function that takes 2 arguments. Basically, I want it to do this: x(n+1)=a*sin[x(n)] and generate a list of x0,x1,x2 etc. up to x(n) like NestList does, starting from x0=1.0 So I want to make a list of these iterations, where a is a constant of my choice, and n is the number of iterations. My first guess was to try iteration[a_,n_]:=NestList[a*Sin,1.0,n] but of course it doesn't work as Mathematica doesnt recognize a*Sin as a function. So I tried defining a function acos[a_,x_]:=a*Sin[x] first but not only does it look inefficient to define 2 functions for something this simple, it also introduces another argument, and I still can't find a way to get it to work. Thanks!