Checking an expression in terms of "n" not x

I am sure I’ve seen something on this, but my brain is just not clicking on it. Wanting students to enter an expression where x=f(n) and then check it using the calculator.

A couple of graph calculation errors. Rewrite your functions v, w and your values D, d as follows:

Thanks that worked! Also realized I had swapped my thinking on which input V was and which was W! Will have to adjust it so students can enter formulas in either locations.