[jtanderson]

Also: a linear function plus a constant is said to be affine!

Reference: https://mathworld.wolfram.com/AffineFunction.html

[phkahler]

I just learned something. Is it correct to call both of the first order? Or is that term really only to be used for the underlying polynomials?

[dan-robertson]

I think of nth order as mostly just applying to approximations. But I guess first order would be ok here.