The sum and difference of two functions are defined as follows.
If \(f\) and \(g\) are two functions, the sum function, denoted by \(f + g\), is defined by
\[(f + g)(x) = f(x) + g(x)\]
Similarly, the difference function, denoted by \(f - g\), is defined by
\[(f-g)(x) = f(x) - g(x)\]
The sum or difference of two functions is a function whose domain is the set of all real numbers that are in the domain of both \(f\) and \(g\).