No problem at all. I understand that writing expressions isn't for everyone. If you'd prefer to create this effect using nodes, you can simply input just the XSplinePosition Variable on it's own in an arithmetic operator. This will then act as though we had added an operator that performs that function, and you can build the rest of the equation using additional arithmetic, constant and variable nodes. Personally I find writing an expression neater but I know many people prefer to stay node based. See attached for the same expression created in this way.