So clearly order mattres a lot.
go f of x and f of g of x, using these two equations give us completely
different expressions. We need to be super careful which
function we’re using as the input for the other one.
What if our functions were f of x equals x squared minus four?
And g of x equals the square root of 4 minus x squared.
Then what will we get for f of g of x or f composed of g?