If you don't like how someone answers your questions, you don't have to ask them.
Also, the answers in example 2 suggest something false about linear functions. Take f(x) = x + 1. f(a) + f(b) = a + b + 2 != f(a+b) = a + b + 1
Also, the answers in example 2 suggest something false about linear functions. Take f(x) = x + 1. f(a) + f(b) = a + b + 2 != f(a+b) = a + b + 1
Maybe you are thinking by a first-degree polynomial, which is a straight line when graphed?